articles+ search results

printing, additive manufacturing (AM), ceramics, rectangular waveguides, rapid prototyping, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999

Ceramic materials are chemical- and temperature-resistant and, therefore, enable novel application fields ranging from automotive to aerospace. With this in mind, this contribution focuses on developing an additive manufacturing approach for 3D-printed waveguides made of ceramic materials. In particular, a special design approach for ceramic waveguides, which introduces non-radiating slots into the waveguides sidewalls, and a customized metallization process, are presented. The developed process allows for using conventional stereolithographic desktop-grade 3D-printers. The proposed approach has, therefore, benefits such as low-cost fabrication, moderate handling effort and independence of the concrete waveguide geometry. The performance of a manufactured ceramic WR12 waveguide is compared to a commercial waveguide and a conventionally printed counterpart. For that reason, relevant properties, such as surface roughness and waveguide geometry, are characterized. Parsing the electrical measurements, the ceramic waveguide specimen features an attenuation coefficient of 30–60 dB/m within the E-Band. The measured attenuation coefficient is 200% and 300% higher compared to the epoxy resin and the commercial waveguide and is attributed to the increased surface roughness of the ceramic substrate.

overconstrained mechanisms, kinematical analysis, automotive application, virtual prototyping, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999

The paper presents some possible applications started from a six revolute joints (6R) overconstrained mechanism. The spatial devices obtained are based on the 6R Wohlhart symmetric mechanism in a special spatial position, with three non-adjacent joints constrained to remain in a fixed plane. This special spatial disposition allows us to obtain some reconfigurable/foldable devices, with an estimated application in the automotive industry field.

integrated intelligent CAD system, springs, parametric 3D modelling, FEM analysis, prototyping, C#, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999

This paper presents the development and implementation of integrated intelligent CAD (computer aided design) system for design, analysis and prototyping of the compression and torsion springs. The article shows a structure of the developed system named Springs IICAD (integrated intelligent computer aided design). The system bounds synthesis and analysis design phases by means of the utilization of parametric 3D (three-dimensional) modeling, FEM (finite element method) analysis and prototyping. The development of the module for spring calculation and system integration was performed in the C# (C Sharp) programming language. Three-dimensional geometric modeling and structural analysis were performed in the CATIA (computer aided three-dimensional interactive application) software, while prototyping is performed with the Ultimaker 3.0 3D printer with support of Cura software. The developed Springs IICAD system interlinks computation module with the basic parametric models in such a way that spring calculation, shaping, FEM analysis and prototype preparation are performed instantly.

design method, joint design, segmentation, additive manufacturing, rapid prototyping, fused deposition modeling (FDM), Technology, Engineering design, and TA174

Rapid prototyping has become increasingly popular over the past years. However, its application is heavily confined to a part size that fits the small build volume of additive machines. This paper presents a universal design method to overcome this limitation while preserving the economic advantages of rapid prototyping over conventional processes. It segments large, thin-walled parts and joins the segments. The method aims to produce an assembly with minimal loss to the performance and characteristics of a solid part. Based on a set of requirements, a universal segmentation approach and a novel hybrid joint design combining adhesive bonding and press fitting are developed. This design allows for the force transmission, positioning, and assembly of the segments adaptive to their individual geometry. The method is tailored to fused deposition modeling (FDM) by minimizing the need for support structures and actively compensating for manufacturing tolerances. While a universal application cannot be guaranteed, the adaptive design was proven for a variety of complex geometries. Using automotive trim parts as an example, the usability, benefits, and novelty of the design method is presented. The method itself shows a high potential to overcome the build volume limitation for thin-walled parts in an economic manner.

sculpture, arduino, marble, design, carving tool, prototyping, Electronics, and TK7800-8360

The art of sculpting is related to the processing of brittle materials, such as granite, marble, and stone, and is implemented using percussive hand tools or rotational roughing tools. The outcome of percussion carving is still directly related to the technique, experience, and capacity of the sculptor. Any attempt to automate the art of sculpturing is exhausted in the subtraction method of brittle materials using a rotating tool. In the process of percussion carving, there is no equivalent expertise. In this work, we present the design, manufacturing (3D printing and CNC machining), and use of a smart, percussion carving tool, either manually by the hand of a sculptor, adjusted in a percussive pneumatic hammer, or guided by a digitally driven machine. The scope is to measure and record the technological variables and sizes that describe and document the carving process through the sensors and electronic devices that the smart tool incorporates, the development and programming of which was implemented for the purposes of this work. The smart carving tool was meticulously tested in various carving stones and stressing scenarios to test the functionality and efficacy of the tool. All the tests were successfully implemented according to the specifications set.

neural network, variable step size, maximum power point tracking, incremental conductance method, Electronics, and TK7800-8360

In conventional adaptive variable step size (VSS) maximum power point tracking (MPPT) algorithms, a scaling factor is utilized to determine the required perturbation step. However, the performance of the adaptive VSS MPPT algorithm is essentially decided by the choice of scaling factor. In this paper, a neural network assisted variable step size (VSS) incremental conductance (IncCond) MPPT method is proposed. The proposed method utilizes a neural network to obtain an optimal scaling factor that should be used in current irradiance level for the VSS IncCond MPPT method. Only two operating points on the characteristic curve are needed to acquire the optimal scaling factor. Hence, expensive irradiance and temperature sensors are not required. By adopting a proper scaling factor, the performance of the conventional VSS IncCond method can be improved, especially under rapid varying irradiance conditions. To validate the studied algorithm, a 400 W prototyping circuit is built and experiments are carried out accordingly. Comparing with perturb and observe (P&O), α-P&O, golden section and conventional VSS IncCond MPPT methods, the proposed method can improve the tracking loss by 95.58%, 42.51%, 93.66%, and 66.14% under EN50530 testing condition, respectively.

polydimethylsiloxane, PDMS properties, PDMS applications, microfluidics, biomedical engineering, Biotechnology, TP248.13-248.65, Medicine (General), and R5-920

Polydimethylsiloxane (PDMS) is an elastomer with excellent optical, electrical and mechanical properties, which makes it well-suited for several engineering applications. Due to its biocompatibility, PDMS is widely used for biomedical purposes. This widespread use has also led to the massification of the soft-lithography technique, introduced for facilitating the rapid prototyping of micro and nanostructures using elastomeric materials, most notably PDMS. This technique has allowed advances in microfluidic, electronic and biomedical fields. In this review, an overview of the properties of PDMS and some of its commonly used treatments, aiming at the suitability to those fields’ needs, are presented. Applications such as microchips in the biomedical field, replication of cardiovascular flow and medical implants are also reviewed.

additive manufacturing, 3D printing, tag, traceability, provenance, anti-counterfeiting, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, and QC120-168.85

Additive manufacturing (AM) is rapidly evolving from “rapid prototyping” to “industrial production”. AM enables the fabrication of bespoke components with complicated geometries in the high-performance areas of aerospace, defence and biomedicine. Providing AM parts with a tagging feature that allows them to be identified like a fingerprint can be crucial for logistics, certification and anti-counterfeiting purposes. Whereas the implementation of an overarching strategy for the complete traceability of AM components downstream from designer to end user is, by nature, a cross-disciplinary task that involves legal, digital and technological issues, materials engineers are on the front line of research to understand what kind of tag is preferred for each kind of object and how existing materials and 3D printing hardware should be synergistically modified to create such tag. This review provides a critical analysis of the main requirements and properties of tagging features for authentication and identification of AM parts, of the strategies that have been put in place so far, and of the future challenges that are emerging to make these systems efficient and suitable for digitalisation. It is envisaged that this literature survey will help scientists and developers answer the challenging question: “How can we embed a tagging feature in an AM part?”.

additive manufacturing, electronic skin, Low-Force Stereolithography, room-temperature-vulcanizing, RTV, single-walled carbon nanotubes, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, and QC120-168.85

The strategy of embedding conductive materials on polymeric matrices has produced functional and wearable artificial electronic skin prototypes capable of transduction signals, such as pressure, force, humidity, or temperature. However, these prototypes are expensive and cover small areas. This study proposes a more affordable manufacturing strategy for manufacturing conductive layers with 6 × 6 matrix micropatterns of RTV-2 silicone rubber and Single-Walled Carbon Nanotubes (SWCNT). A novel mold with two cavities and two different micropatterns was designed and tested as a proof-of-concept using Low-Force Stereolithography-based additive manufacturing (AM). The effect SWCNT concentrations (3 wt.%, 4 wt.%, and 5 wt.%) on the mechanical properties were characterized by quasi-static axial deformation tests, which allowed them to stretch up to ~160%. The elastomeric soft material’s hysteresis energy (Mullin’s effect) was fitted using the Ogden–Roxburgh model and the Nelder–Mead algorithm. The assessment showed that the resulting multilayer material exhibits high flexibility and high conductivity (surface resistivity ~7.97 × 104 Ω/sq) and that robust soft tooling can be used for other devices.

micromachining strategies, micro/mesoscale milling, 3D microfluidic structure, PMMA, PDMS, surface quality, Mechanical engineering and machinery, and TJ1-1570

In recent years, there has been an increased interest in exploring the potential of micro-and mesoscale milling technologies for developing cost-effective microfluidic systems with high design flexibility and a rapid microfabrication process that does not require a cleanroom. Nevertheless, the number of current studies aiming to fully understand and establish the benefits of this technique in developing high-quality microsystems with simple integrability is still limited. In the first part of this study, we define a systematic and adaptable strategy for developing high-quality poly(methyl methacrylate) (PMMA)-based micromilled structures. A case study of the average surface roughness (Ra) minimization of a cuboid column is presented to better illustrate some of the developed strategies. In this example, the Ra of a cuboid column was reduced from 1.68 μm to 0.223 μm by implementing milling optimization and postprocessing steps. In the second part of this paper, new strategies for developing a 3D microsystem were introduced by using a specifically designed negative PMMA master mold for polydimethylsiloxane (PDMS) double-casting prototyping. The reported results in this study demonstrate the robustness of the proposed approach for developing microfluidic structures with high surface quality and structural integrability in a reasonable amount of time.

SU-8, photoresist, polydimethylsiloxane (PDMS), maskless photolithography, grayscale photolithography, backside exposure, Mechanical engineering and machinery, and TJ1-1570

Organ-on-a-chip (OoC) and microfluidic devices are conventionally produced using microfabrication procedures that require cleanrooms, silicon wafers, and photomasks. The prototyping stage often requires multiple iterations of design steps. A simplified prototyping process could therefore offer major advantages. Here, we describe a rapid and cleanroom-free microfabrication method using maskless photolithography. The approach utilizes a commercial digital micromirror device (DMD)-based setup using 375 nm UV light for backside exposure of an epoxy-based negative photoresist (SU-8) on glass coverslips. We show that microstructures of various geometries and dimensions, microgrooves, and microchannels of different heights can be fabricated. New SU-8 molds and soft lithography-based polydimethylsiloxane (PDMS) chips can thus be produced within hours. We further show that backside UV exposure and grayscale photolithography allow structures of different heights or structures with height gradients to be developed using a single-step fabrication process. Using this approach: (1) digital photomasks can be designed, projected, and quickly adjusted if needed; and (2) SU-8 molds can be fabricated without cleanroom availability, which in turn (3) reduces microfabrication time and costs and (4) expedites prototyping of new OoC devices.

FDM, 3D printing, additive manufacturing, shear test, adhesion, Organic chemistry, and QD241-441

Additive Manufacturing (AM) became a popular engineering solution not only for Rapid Prototyping (RP) as a part of product development but as an effective solution for producing complex geometries as fully functional components. Even the modern engineering tools, such as the different simulation software, have a shape optimization solution especially for parts created by AM. To extend the application of these methods in this work, the failure properties of the 3D-printed parts have been investigated via shear test measurements. The layer adhesion can be calculated based on the results, which can be used later for further numerical modeling. In conclusion, it can be stated that the layer formation and the structure of the infill have a great influence on the mechanical properties. The layers formed following the conventional zig-zag infill style show a random failure, and the layers created via extruded concentric circles show more predictable load resistance.

Industry 4.0, Digital Twin, simulation modelling, Chemical technology, TP1-1185, Chemistry, and QD1-999

This article presents the most valuable and applicable open-source tools and communication technologies that may be employed to create models of production processes by applying the concept of Digital Twins. In recent years, many open-source technologies, including tools and protocols, have been developed to create virtual models of production systems. The authors present the evolution and role of the Digital Twin concept as one of the key technologies for implementing the Industry 4.0 paradigm in automation and control. Based on the presented structured review of valuable open-source software dedicated to various phases and tasks that should be realised while creating the whole Digital Twin system, it was demonstrated that the available solutions cover all aspects. However, the dispersion, specialisation, and lack of integration cause this software to usually not be the first choice to implement DT. Therefore, to successfully create full-fledged models of Digital Twins by proceeding with proposed open-source solutions, it is necessary to make additional efforts due to integration requirements.

additive manufacturing, 3d printing, china, Economics as a science, and HB71-74

Additive manufacturing - or three-dimensional (3D) printing - refers to a group of technologies characterised by an accelerating maturation trend, which allow the creation of three-dimensional objects based on digital models, by sequentially applying and integrating layers of various traditional and innovative materials, from metals, polymers and ceramics, to graphene and other nanomaterials and composites. The technologies have applications in a variety of industries, from consumer goods production, automotive and aircraft parts, architecture and construction, to medical services and devices, or research and defence. Globally, the additive manufacturing market, which includes equipment, materials and 3D printing as a service, as well as their applications for prototyping and rapid manufacturing, has been valued at USD 15.4billion in 2020, with existing projections reflecting a four-fold increase to USD 61.1 billion in 2027. By the same date, China – the current 'factory of the world' – is projected to have a significant but less than one-quarter share of the global market – USD14.5 billion – against the backdrop of existing gaps difficult to narrow down.

aphasia, assistive technology, storytelling, user-centered design, graphical user interface, usability tests, Chemical technology, and TP1-1185

Aphasia is a partial or total loss of the ability to articulate ideas or comprehend spoken language, resulting from brain damage, in a person whose language skills were previously normal. Our goal was to find out how a storytelling app can help people with aphasia to communicate and share daily experiences. For this purpose, the Aphasia Create app was created for tablets, along with Aphastory for the Google Glass device. These applications facilitate social participation and enhance quality of life by using visual storytelling forms composed of photos, drawings, icons, etc., that can be saved and shared. We performed usability tests (supervised by a neuropsychologist) on six participants with aphasia who were able to communicate. Our work contributes (1) evidence that the functions implemented in the Aphasia Create tablet app suit the needs of target users, but older people are often not familiar with tactile devices, (2) reports that the Google Glass device may be problematic for persons with right-hand paresis, and (3) a characterization of the design guidelines for apps for aphasics. Both applications can be used to work with people with aphasia, and can be further developed. Aphasic centers, in which the apps were presented, expressed interest in using them to work with patients. The Aphasia Create app won the Enactus Poland National Competition in 2015.

port community system, terminal operating system, navigation safety, logistics, e-freight, IoT-based monitoring, Chemical technology, and TP1-1185

Seaports are genuine, intermodal hubs connecting seaways to inland transport links, such as roads and railways. Seaports are located at the focal point of institutional, industrial, and control activities in a jungle of interconnected information systems. System integration is setting considerable challenges when a group of independent providers are asked to implement complementary software functionalities. For this reason, seaports are the ideal playground where software is highly composite and tailored to a large variety of final users (from the so-called port communities). Although the target would be that of shaping the Port Authorities to be providers of (digital) innovation services, the state-of-the-art is still that of considering them as final users, or proxies of them. For this reason, we show how a canonical cloud, virtualizing a distributed architecture, can be structured to host different, possibly overlapped, tenants, slicing the information system at the infrastructure, platform, and software layers. Resources at the infrastructure and platform layers are shared so that a variety of independent applications can make use of the local calculus and access the data stored in a Data Lake. Such a cloud is adopted by the Port of Livorno as a rapid prototyping framework for the development and deployment of ICT innovation services. In order to demonstrate the versatility of this framework, three case studies relating to as many prototype ICT services (Navigation Safety, e-Freight, and Logistics) released within three industrial tenants are here presented and discussed.

Shape memory polyurethane, Magnesium, 3D printing, Robust bone regeneration, Tight-contact, Materials of engineering and construction. Mechanics of materials, TA401-492, Biology (General), and QH301-705.5

Patients with bone defects suffer from a high rate of disability and deformity. Poor contact of grafts with defective bones and insufficient osteogenic activities lead to increased loose risks and unsatisfied repair efficacy. Although self-expanding scaffolds were developed to enhance bone integration, the limitations on the high transition temperature and the unsatisfied bioactivity hindered greatly their clinical application. Herein, we report a near-infrared-responsive and tight-contacting scaffold that comprises of shape memory polyurethane (SMPU) as the thermal-responsive matrix and magnesium (Mg) as the photothermal and bioactive component, which fabricated by the low temperature rapid prototyping (LT-RP) 3D printing technology. As designed, due to synergistic effects of the components and the fabrication approach, the composite scaffold possesses a homogeneously porous structure, significantly improved mechanical properties and stable photothermal effects. The programmed scaffold can be heated to recover under near infrared irradiation in 60s. With 4 wt% Mg, the scaffold has the balanced shape fixity ratio of 93.6% and shape recovery ratio of 95.4%. The compressed composite scaffold could lift a 100 g weight under NIR light, which was more than 1700 times of its own weight. The results of the push-out tests and the finite element analysis (FEA) confirmed the tight-contacting ability of the SMPU/4 wt%Mg scaffold, which had a signficant enhancement compared to the scaffold without shape memory effects. Furthermore, The osteopromotive function of the scaffold has been demonstrated through a series of in vitro and in vivo studies. We envision this scaffold can be a clinically effective strategy for robust bone regeneration.

Digital signal processor, Universal motor, Speed control, Hardware architecture, PI controller, dSPACE MicroAutoBox, Engineering (General). Civil engineering (General), and TA1-2040

Universal motors are widely used in household appliances. When traditionally powered by AC, current harmonics are created which cause overheating of the windings and electromagnetic compatibility problems affecting the lifespan of the motor. Considering the remarkable comeback of DC power and its prospects in the electrification of homes, this paper proposes a control strategy for universal motors powered by DC using the rapid control prototyping feature offered by the dSPACE MicroAutoBox. A PI controller is designed using dominant-pole compensation method. The control strategy is simulated in Matlab/Simulink, then implemented in the MicroAutoBox via the Real-Time Interface. The simulation results are compared with those acquired by implementation through a laboratory test bench built around the MicroAutoBox and a dual full-bridge driver. The experimental results show that the designed PI controller managed to eliminate the static error and increased significantly the system dynamic performance by 26.5% in simulation and by 23.5% in practice. The robustness of the proposed control strategy against randomized load disturbances is proved by experimental tests. Furthermore, a significant improvement in power quality is reported.

Drones, CFD, MDO, Aircraft design, Open source, PSO, Computer engineering. Computer hardware, TK7885-7895, Electronic computers. Computer science, and QA75.5-76.95

Hybrid configurations in aircraft design are highly favorable as they can achieve the appropriate trade-offs required to develop a generalized unmanned aerial system (UAS). Rapid prototyping of such systems at the student level is challenging because commercial software is expensive and difficult to interlink with other tools for creating a multi-disciplinary design. We address this challenge by conceptualizing an aircraft design framework made entirely of open-source software, libraries, and in-house code. We then use this framework to design an all-electric unmanned aerial system with transitioning Vertical Take-off and Landing (VTOL) and Fixed-Wing (FW) modes. The UAV is capable of long-range surveillance up to 100 Kilometers and carrying a maximum relief payload of 1 kg while operating in an ad-hoc wi-fi network with a swarm of similar UAVs. A low fidelity particle swarm optimization algorithm (PSO) and a comprehensive propulsion architecture is also incorporated and validated against commercial software. To validate the design, a prototype is fabricated from glass-fiber and XPS foam, integrated with appropriate sensors and tuned using ArduPilot software. The results show that low-fidelity design is a safe starting point for prototyping under constrained timelines. The study is concluded by discussing the technical challenges of using free software, and some practical considerations while flight testing a UAV with a hybrid configuration.

nanoparticles, self-assembly, printing technology, patterned structure, functional devices, Science (General), and Q1-390

Functional nanoparticles (NPs) with unique photoelectric, mechanical, magnetic, and chemical properties have attracted considerable attention. Aggregated NPs rather than individual NPs are generally required for sensing, electronics, and catalysis. However, the transformation of functional NP aggregates into scalable, controllable, and affordable functional devices remains challenging. Printing is a promising additive manufacturing technology for fabricating devices from NP building blocks because of its capabilities for rapid prototyping and versatile multifunctional manufacturing. This paper reviews recent advances in NP patterning based on the combination of self-assembly and printing technologies (including two-, three-, and four-dimensional printing), introduces the basic characteristics of these methods, and discusses various fields of NP patterning applications. Public summary: • Nanoparticles (NPs) printing assembly is a good solution for patterned devices • NPs assembly can be combined with 2D, 3D, and 4D printing technologies • A variety of ink-dispersed NPs are available for printing assembly • NPs printing assembly technology is applied for nanosensing, energy storage, photodetector

3d printing, Additive manufacturing, Rapid prototyping, Surgery, Craniofacial, Maxillofacial, Medical technology, and R855-855.5

This systematic review aims to provide an overview of the published literature for three-dimensional printing (3DP) in cranio- and maxillofacial surgery applications utilizing either external laboratories (outsourced) or point-of-care (POC) fabrication facilities. Four digital databases (PubMed, Web of Science, Embase, and Cochrane Library) were systematically reviewed between January 2018 and December 2020. The review focused on the type of printed objects, the clinical indications, surgical outcome, time, cost, 3DP materials, and technologies used. Among the 2269 retrieved studies, 75 met the inclusion criteria. The studies that stated POC and outsourced production methods were 34.67% (n = 26) and 12% (n = 9). A large proportion of studies (54.67%, n = 41) did not specify the printing location. 3DP was used for surgeries of the entire craniomaxillofacial region, most specifically in mandibular reconstructions and orthognathic surgeries applications. Customized implants and osteosynthesis plates were exclusively printed in titanium using Powder Bed Fusion (PBF) 3DP technology. For surgical guides, models, and molds, Material Jetting, Material Extrusion, and Vat Photopolymerization, using either thermoplastic or photopolymeric resin materials were used. Medical 3DP is an assisting tool to plan, prepare, and even improve cranio- and maxillofacial surgery outcomes. With future technological advancement and research, 3DP has the potential to revolutionize cranio- and maxillofacial surgeries. With decreasing prices of three-dimensional (3D) printers and software packages, the disadvantage of the high acquisition and procurement costs for the hardware for in-house 3DP can be addressed and mitigated with time.

virtual reality laboratory, automotive industry, Education 4.0, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999

Knowledge transfer associated with education in the automotive manufacturing and production fields is challenging due to the requirements of physical prototyping of mechanical components and laboratory-assisted testing. In this regard, aspects of Industry 4.0 such as virtual environments and enhanced human–computer interaction have been studied as important resources to improve teaching practices and achieve the equivalent Education 4.0 paradigm. Within the context of modern manufacturing techniques in the Industry 4.0 era and advanced tools for analysis and mechanical design, the present work describes the development of a virtual/augmented reality (VR/AR) laboratory to support learning, training, and collaborative ventures related to additive manufacturing for the automotive industry. The development was performed in accordance with the guidelines of the ISO/IEC TR 23842-1 standard, to ensure that the academic programs and the conditions of use of the laboratory were optimal. Experiences with students through the development of industry-related automotive projects support confidence in the suitability of the laboratory and the expectation of positive outcomes for future developments.

Physics, QC1-999, Biology (General), and QH301-705.5

Super-resolution optical fluctuation imaging (SOFI) is a highly democratizable technique that provides optical super-resolution without requirement of sophisticated imaging instruments. Easy-to-use open-source packages for SOFI are important to support the utilization and community adoption of the SOFI method, they also encourage the participation and further development of SOFI by new investigators. In this work, we developed PySOFI, an open-source Python package for SOFI analysis that offers the flexibility to inspect, test, modify, improve, and extend the algorithm. We provide complete documentation for the package and a collection of Jupyter Notebooks to demonstrate the usage of the package. We discuss the architecture of PySOFI and illustrate how to use each functional module. A demonstration on how to extend the PySOFI package with additional modules is also included in the PySOFI package. We expect PySOFI to facilitate efficient adoption, testing, modification, dissemination, and prototyping of new SOFI-relevant algorithms.

Clay industries. Ceramics. Glass and TP785-869

This research revolves around the design, fabrication and testing of tubular glass columns, with particular focus on their redundancy and fire-safety mechanisms; moreover, addressing aspects such as: the column shape; cleaning and maintenance; end connections; geometric tolerances in the glass and demountability. Two alternative circular hollow (tube) column designs are initially developed and engineered to address these aspects, namely: the MLA (Multi Layered with Air) and the SLW (Single Layered with water). In both concepts the main load-bearing structure consists of two concentric laminated glass tubes. Thus, in order to explore the manufacturing challenges and structural potential of these concepts, the prototyping and experimental work focuses on six 300 mm long samples with 115 mm outer diameter that are laminated and fitted into customized, engineered steel end-connections. Particular attention in terms of manufacturing is paid to the lamination process and associated bubble formation, the possible fracture of the glass by internal resin-curing stresses and the interface between the glass tube and the steel end-connections. All samples are laminated with Ködistruct LG 2-PU component. Three samples are assembled using DURAN® (annealed) glass and the other three are using DURATAN® (heat-strengthened) glass. Subsequently, the six samples are tested in compression until failure to investigate the behaviour of the interlayer material, the post-fracture behaviour of the designs, the differences between annealed and heat-strengthened samples, the capacity of the glass tubes and the performance of the end connections. Initial cracks appeared between 95-160 kN (compression strength of 30-50 MPa) in the DURAN® samples and between 120-160 kN (compression strength of 37-50 MPa) in the DURATAN® samples. These loads are lower than the ones estimated by calculations; in specific, the first cracks occurred at 34-64% of the calculated load. Nevertheless, the samples are found to be robust, with a considerable load-bearing capacity beyond the first cracks, leading to a maximum nominal compression strength capacity of up to 152 MPa for the DURATAN® samples and up to 233 MPa for the DURAN® samples.

Rapid Control Prototyping, Modular Multilevel Converter, Sinusoidal Pulse Width Modulation, Induction Motor, Typhoon HIL, Engineering (General). Civil engineering (General), and TA1-2040

In this paper, Rapid Control Prototyping (RCP) of five-level Modular Multilevel Converter (MMC) based Induction Motor (IM) drive performance is observed with different switching frequencies. The Semikron based MMC Stacks with two half-bridge each are tested with the switching logic generated by phase and level shifted based Sinusoidal Pulse Width Modulation (SPWM) technique. The switching logic is generated by the Typhoon Hardware in Loop (HIL) 402. The disadvantages of Multilevel Converter like not so good output quality, less modularity, not scalable and high voltage and current rating demand for the power semiconductor switches can be overcome by using MMC. In this work, the IM drive is fed by MMC and the experimentally the performance is observed. The performance of the Induction Motor in terms of speed is observed with different switching frequencies of 2.5kHz, 5kHz, 7.5kHz, 10kHz, 12.5kHz and the results are tabulated in terms of Total Harmonic Distortion (THD) of input voltage and current to the Induction Motor Drive. The complete model is developed using Typhoon HIL 2021.2 Version Real-Time Simulation Software.

3D printing, Fused deposition modeling (FDM), Tensile strength, Thermoplastics, Polylactic acid (PLA), Design of experiments (DOE), and Technology

Fused deposition modeling (FDM), one of various additive manufacturing (AM) technologies, offers a useful and accessible tool for prototyping and manufacturing small volume functional parts. Polylactic acid (PLA) is among the commonly used materials for this process. This study explores the mechanical properties and print time of additively manufactured PLA with consideration to various process parameters. The objective of this study is to optimize the process parameters for the fastest print time possible while minimizing the loss in ultimate strength. Design of experiments (DOE) was employed using a split-plot design with five factors. Analysis of variance (ANOVA) was employed to verify the model significance or otherwise. Once the model was developed, confirmation points were run to validate the model. The model was confirmed since the observations at the optimum were within the prediction interval with a confidence value of 95%. Then, the model was used to assess the ultimate strength and print time of FDM parts with consideration to nozzle diameter, the number of outer shells, extrusion temperature, infill percentage, and infill pattern. Recommendations are discussed in detail in this study to reduce print time without sacrificing significant part strength.

virtual product development, vehicle virtual design, stylistic design engineering (SDE), car design, industrial design, design engineering, Engineering machinery, tools, and implements, TA213-215, Technological innovations. Automation, and HD45-45.2

In this paper, industrial design structure (IDeS) is applied for the development of two new full-electric sports sedan car proposals that go by the names Blitz Vision AS and Retro. With a deep analysis of the trends dominating the automotive industry, a series of product requirements was identified using quality function deployment (QFD). The results of such analysis led to the definition of the technical specifications of the product via benchmarking (BM) and top-flop analysis (TFA). The product architecture was then defined by making use of a modular platform chassis capable of housing a variety of vehicle bodyworks. The structured methodology of stylistic design engineering (SDE) was used. This can be divided in six phases: (1) stylistic trends analysis; (2) sketches; (3) 2D CAD drawings; (4) 3D CAD models; (5) virtual prototyping; (6) solid stylistic model. The chassis of the CAD model was verified structurally by means of FEM analysis, whereas the drag coefficients of the two vehicle proposals were compared with one of the main competitor’s vehicles via CFD simulations. The resulting car models are both aesthetically appealing and can be further developed, leading eventually to the production stage. This proves the effectiveness of IDeS and SDE in car design.

Tissue P System, Wireless Sensor Network, Multi-Objective problem, Task Assignment, Decision Support System, Parallel computing, Electronic computers. Computer science, and QA75.5-76.95

The contemporary wireless sensor applications employ a Heterogeneous Wireless Sensor Network (HeWSN) to achieve its multi-objective missions. Modern wireless nodes constituting the HeWSN are more versatile in terms of its capabilities, functionalities, and applications. Assigning tasks in a dynamic HeWSN environment are challenging due to its inherent heterogeneous properties and capabilities. The investigation of existing task assignment algorithms reveals (i) the majority of the existing task assignment algorithms were designed for the homogeneous environment, (ii) most of the nature-inspired algorithms were built for centralized architecture. Scheduling tasks by existing task assignment algorithms lead to underutilization of resources as well as to the rapid depletion of network resources. To this end, a novel, distributed, heterogeneous task assignment algorithm adhering the modern sensors capabilities, functionalities and sensor application to attain sustainable computing is required. Based on the investigation, Tissue P-System inspired task assignment algorithm for the distributed heterogeneous WSN has been modelled. The experimental analyses of the proposed method have been self-evaluated as well as compared with the corresponding recent benchmark algorithms under various conditions and its performance metrics are analysed.

gear system, gear backlash, bearing clearance, nonlinear dynamic characteristic, system stability, Mechanical engineering and machinery, and TJ1-1570

In practice, gear backlash and bearing clearance usually exist together in a gear system. They may induce complicated dynamic responses and degrade transmission performance. Up to now, although each of them has been researched, little attention has been paid to the coupling dynamic characteristics of gear backlash and bearing clearance. In a limited number of relevant studies, since the linear collision models they adopted are difficult to realistically depict actual collision behaviors caused by bearing clearance, these studies cannot accurately reveal the coupling dynamic characteristics of gear backlash and bearing clearance. Furthermore, system stability of the gear system considering gear backlash and bearing clearance has not been thoroughly investigated. In view of this, this paper contributes to the research on dynamic modeling and stability analysis for the spur gear system considering gear backlash and bearing clearance. A nonlinear collision model with time-varying contact stiffness/damping is suggested for describing the bearing collision behaviors. Based on the geometrical relationship of dynamic center distance, dynamic working pressure angle, and dynamic backlash, the coupling motion model of gear backlash and bearing clearance is developed. On this basis, the dynamic model of the spur gear system considering gear backlash and bearing clearance is established and verified by numerical simulations, virtual prototyping simulations and experiments. Afterwards, to thoroughly explore the complicated dynamic characteristics of the gear system considering gear backlash and bearing clearance, several important parameters, i.e., rotational speed, gear backlash and bearing clearance, are chosen as bifurcation parameters to study their influences on system stability via bifurcation diagrams, time-domain waveforms, FFT spectra, Poincaré maps, and phase diagrams. Various complicated nonlinear behaviors, such as hopping, multiple periodic motion, quasi-periodic motion, and chaotic motion, are revealed. This study can provide useful reference for the multi-clearance coupling research of the gear system in complicated working environments.

acid mud, resource recovery, microwave heating, conventional heating, mercury pollution reduction, Mining engineering. Metallurgy, and TN1-997

The acid mud produced in the nonferrous smelting process is a hazardous waste, which mainly consists of elements Hg, Se, and Pb. Valuable metal (Hg/Se/Pb) can be recovered from acid mud by heat treatment. For safe disposal of the toxic acid mud, a new resource utilization technology by microwave roasting is proposed in this paper. The reaction mechanisms were revealed through thermodynamics and thermogravimetric analysis, which showed that the main reaction was the oxidative pyrolysis of HgSe in the process of roasting. Moreover, the mercury removal effects of acid mud by microwave heating and conventional heating were studied, the recovery rate of mercury by microwave heating for 30 min at 400 °C was 99.5%: far higher than that of conventional heating for 30 min at 500 °C (44.3%). This was due to the high dielectric constant of HgSe, as microwaves can preferentially heat HgSe and reduce the adsorption energy of HgSe on the surface of PbSO4 blocks, thus strengthening the pyrolysis process of HgSe and reducing energy consumption. The preferable prototyping technology for resource utilization of toxic acid mud should be microwave roasting. This study is of great significance for the realization of mercury pollution reduction and for green production of lead-zinc smelting.

Science

An attractive route for carbon-negative synthesis of biochemical products is the reverse β-oxidation pathway coupled to the Wood-Ljungdahl pathway. Here the authors use a high-throughput in vitro prototyping workflow to screen 762 unique pathway combinations using cell-free extracts tailored for r-BOX to identify enzyme sets for enhanced product selectivity.

Bone regeneration, Hydroxyapatite, Larnite, Scaffold, Selective laser melting, Wollastonite, Clay industries. Ceramics. Glass, and TP785-869

Additive manufacturing is a rapid prototyping technology to produce complex three-dimensional scaffolds suitable for personalized medicine. In the present study, the laser powder bed fusion through a selective laser melting (SLM) approach has been applied to optimized fabrication of bio-mimicking scaffolds by using hydroxyapatite (HAp, 50 and 70 wt%) and silicon powder mixture. In situ formation of pseudo-wollastonite (P–W, CaSiO3) has been detected along with silicon for 50 wt% of HAp powder mixture, while an increase in HAp content has resulted in P–W, silicon and larnite (Ca₂SiO₄) formation. The pore size of 400 μm, according to the CAD model, are observed at the scaffolds fabricated at the shortest exposure time (50 μs), lowest laser current (500 mA) and energy density (41.6 J/mm3), and simultaneously at the highest scanning speed. Compressive stress demonstrated by the fabricated scaffolds is shown to be acceptable for their use in metaphyseal region of long bones.

Germany, formulation design, manufacturing science, materials science, hotmelt extrusion, spinning process, Pharmacy and materia medica, and RS1-441

Fibers and yarns are part of everyday life. So far, fibers that are also used pharmaceutically have mainly been produced by electrospinning. The common use of spinning oils and the excipients they contain, in connection with production by melt extrusion, poses a regulatory challenge for pharmaceutically usable fibers. In this publication, a newly developed small-scale direct-spinning melt extrusion system is described, and the pharmaceutically useful polyvinyl filaments produced with it are characterized. The major parts of the system were newly developed or extensively modified and manufactured cost-effectively within a short time using rapid prototyping (3D printing) from various materials. For example, a stainless-steel spinneret was developed in a splice design for a table-top melt extrusion system that can be used in the pharmaceutical industry. The direct processing of the extruded fibers was made possible by a spinning system developed called Spinning-Rosi, which operates continuously and directly in the extrusion process and eliminates the need for spinning oils. In order to prevent instabilities in the product, further modifications were also made to the process, such as a the moisture encapsulation of the melt extrusion line at certain points, which resulted in a bubble-free extrudate with high tensile strength, even in a melt extrusion line without built-in venting.

holography, holographic optical elements, volume hologram, Bragg grating, multiplexing, wave front recording, Applied optics. Photonics, and TA1501-1820

We present an array-based volume holographic optical element (vHOE) recorded as an optical combiner for novel display applications such as smart glasses. The vHOE performs multiple, complex optical functions in the form of large off-axis to on-axis wave front transformations and an extended eye box implemented in the form of two distinct vertex points with red and green chromatic functions. The holographic combiner is fabricated by our extended immersion-based wave front printing setup, which provides extensive prototyping capabilities due to independent wave front modulation and large possible off-axis recording angles, enabling vHOEs in reflection with a wide range of different recording configurations. The presented vHOE is build up as an array of sub-holograms, where each element is recorded with individual optical functions. We introduce a design and fabrication method to combine two angular and two spectral functions in the volume grating of individual sub-holograms, demonstrating complex holographic elements with four multiplexed optical functions comprised in a single layer of photopolymer film. The introduced design and fabrication process allows the precise tuning of the vHOE’s diffractive properties to achieve well-balanced diffraction efficiencies and angular distributions between individual multiplexed functions.

inclusion, prototyping, tactile maps, teaching, teaching materials, Education (General), and L7-991

Brazilian society does not guarantee people with disabilities the educational resources that allow for inclusive and egalitarian education for all. We prove the effectiveness and efficiency in the use of computational resources added to the designer's concepts for the development of an innovative and inclusive product. The research was carried out at the Benjamin Constant Institute. The methodology used was evolutionary computing prototyping and the interview technique for the validation of the Map. In the evaluation, we used the interview technique, questionnaires, in addition to non-participant systematic observation. Three geography teachers and ten visually impaired students who studied the proposed content participated. Teachers approved the technology in its characteristics and functionality, respectively, by 90.06% and 97%. Students rated the map features 94.54% and the features a 99.25% approval rating. The research promoted the quality of teaching to students with visual impairments when it allowed them to manage a volume of information about the Southeast Region of Brazil and increased their autonomy in allowing them to repeat any information they had not assimilated, without the need for help.

Medicine and Science

Abstract We present a novel design for an e-textile based surface electromyography (sEMG) suit that incorporates stretchable conductive textiles as electrodes and interconnects within an athletic compression garment. The fabrication and assembly approach is a facile combination of laser cutting and heat-press lamination that provides for rapid prototyping of designs in a typical research environment without need for any specialized textile or garment manufacturing equipment. The materials used are robust to wear, resilient to the high strains encountered in clothing, and can be machine laundered. The suit produces sEMG signal quality comparable to conventional adhesive electrodes, but with improved comfort, longevity, and reusability. The embedded electronics provide signal conditioning, amplification, digitization, and processing power to convert the raw EMG signals to a level-of-effort estimation for flexion and extension of the elbow and knee joints. The approach we detail herein is also expected to be extensible to a variety of other electrophysiological sensors.

deep neural networks, High-Level Synthesis, hardware accelerators, FPGAs, sparse neural networks, Chemical technology, and TP1-1185

Convolution Neural Networks (CNNs) are gaining ground in deep learning and Artificial Intelligence (AI) domains, and they can benefit from rapid prototyping in order to produce efficient and low-power hardware designs. The inference process of a Deep Neural Network (DNN) is considered a computationally intensive process that requires hardware accelerators to operate in real-world scenarios due to the low latency requirements of real-time applications. As a result, High-Level Synthesis (HLS) tools are gaining popularity since they provide attractive ways to reduce design time complexity directly in register transfer level (RTL). In this paper, we implement a MobileNetV2 model using a state-of-the-art HLS tool in order to conduct a design space exploration and to provide insights on complex hardware designs which are tailored for DNN inference. Our goal is to combine design methodologies with sparsification techniques to produce hardware accelerators that achieve comparable error metrics within the same order of magnitude with the corresponding state-of-the-art systems while also significantly reducing the inference latency and resource utilization. Toward this end, we apply sparse matrix techniques on a MobileNetV2 model for efficient data representation, and we evaluate our designs in two different weight pruning approaches. Experimental results are evaluated with respect to the CIFAR-10 data set using several different design methodologies in order to fully explore their effects on the performance of the model under examination.

UAV, anti-drone system, data fusion, drone detection, identification, recognition, Chemical technology, and TP1-1185

The paper focuses on the problem of detecting unmanned aerial vehicles that violate restricted airspace. The main purpose of the research is to develop an algorithm that enables the detection, identification and recognition in 3D space of a UAV violating restricted airspace. The proposed method consists of multi-sensory data fusion and is based on conditional complementary filtration and multi-stage clustering. On the basis of the review of the available UAV detection technologies, three sensory systems classified into the groups of passive and active methods are selected. The UAV detection algorithm is developed on the basis of data collected during field tests under real conditions, from three sensors: a radio system, an ADS-B transponder and a radar equipped with four antenna arrays. The efficiency of the proposed solution was tested on the basis of rapid prototyping in the MATLAB simulation environment with the use of data from the real sensory system obtained during controlled UAV flights. The obtained results of UAV detections confirmed the effectiveness of the proposed method and theoretical expectations.

Orbital Shaker, Open-source, 3D printing, HTS, Cellular suspension, Biotechnology, TP248.13-248.65, Medical technology, and R855-855.5

Open-source projects continue to grow in popularity alongside open-source educational resources, software, and hardware tools. The impact of this increased availability of open-source technologies is that end users are empowered to have greater control over the tools that they work with. This trend extends in the life science laboratory space, where new open-source projects are routinely being published that allow users to build and modify scientific equipment specifically tailored to their needs, often at a reduced cost from equivalent commercial offerings.Recently, we identified a need for a compact orbital shaker that would be usable in temperature and humidity-controlled incubators to support the development and execution of a high-throughput suspension cell-based assay. Based on the requirements provided by staff biologists, an open-source project known as the DIYbio orbital shaker was identified on Thingiverse, then quickly prototyped and tested. The initial orbital shaker prototype based on the DIYbio design underwent an iterative prototyping and design process that proved to be straightforward due to the open-source nature of the project. The result of these efforts has been the successful initial deployment of ten shakers as of August 2021. This afforded us the scalability and efficacy needed to complete a large-scale screening campaign in less time and at less cost than if we purchased larger, less adaptable orbital shakers.Lessons learned from prototyping, modifying, validating, deploying and maintaining laboratory devices based on an open-source design in support of a full-scale drug discovery high-throughput screening effort are described within this manuscript.

Contiki-NG, Internet of Things, Resource-Constrained Devices, Computer software, and QA76.75-76.765

Contiki-NG (Next Generation) is an open source, cross-platform operating system for severely constrained wireless embedded devices. It focuses on dependable (reliable and secure) low-power communications and standardised protocols, such as 6LoWPAN, IPv6, 6TiSCH, RPL, and CoAP. Its primary aims are to (i) facilitate rapid prototyping and evaluation of Internet of Things research ideas, (ii) reduce time-to-market for Internet of Things applications, and (iii) provide an easy-to-use platform for teaching embedded systems-related courses in higher education. Contiki-NG started as a fork of the Contiki OS and retains many of its original features. In this paper, we discuss the motivation behind the creation of Contiki-NG, present the most recent version (v4.7), and highlight the impact of Contiki-NG through specific examples.

Multiphase, Singlephase, Relative permeability, Permeability, Lattice-Boltzmann, Porous media, Computer software, and QA76.75-76.765

MPLBM-UT is a specialized lattice-Boltzmann library that makes running single- and two-phase flow simulations in porous media accessible to everyone. We provide a suite of tools to pre-process computational domains for simulation, to set up custom boundary conditions, to run simulations, to post-process simulation outputs, and to visualize simulation results and data. All of these tools are easily accessible to users through the mplbm_utils Python package included in and automatically installed with MPLBM-UT. The high-performance, highly parallel library Palabos is used as the solver backend. MPLBM-UT is easily deployed in a variety of systems, from laptops to supercomputer clusters. MPLBM-UT also features multiple examples and benchmark templates that allow for fast prototyping of different porous media problems. We also provide an interface for reading in different file types and downloading domains from the Digital Rocks Portal to perform simulations.

Combinatorial optimization, Hyper-heuristics, Job shop scheduling, Matlab, MatHH, Computer software, and QA76.75-76.765

Hyper-Heuristics (HHs) have proven to be a valuable tool for solving complex problems, such as Combinatorial Optimization Problems (COPs). These solvers have an assorted set of models arising through extensive research from the scientific community. Hence, it is customary that researchers develop their models from scratch, which increases development times. Drafting and testing new ideas become burdensome and time-consuming. In this work, we present MatHH, a Matlab-based framework to allow rapid prototyping of HHs. We summarize the architecture and some examples of their usage. We also discuss some research questions that upcoming research may explore through MatHH.

Cycling infrastructure, Distance to parking cars, Cycling simulator, Online survey, Rapid prototyping, Method comparison, Transportation and communications, and HE1-9990

Marked on-road infrastructure for bicycle riders is a fast and cost-efficient way to expand cycling infrastructure and thus promote cycling as a means of transport. Infrastructure layout has been shown to influence cyclists’ as well as car drivers’ behavior towards cyclists in traffic observations, with on-street markings for cyclists in some circumstances reducing overtaking distances by car drivers. Simulator and online studies promise to provide a fast and easy way of rapid prototyping infrastructure layouts. But, despite of good face validity, how trustworthy are the results of both these research tools? In a case-study to inform planning authorities, two studies, one in a cycling simulator and an online survey, evaluated the effects of different on-street markings from bicycle riders’ perspectives. Results showed that in mixed traffic stronger visual separation between parking cars and flowing traffic and a bicycle pictogram on the road induced greater lateral distance of bicycle riders from parking cars. This infrastructure layout was also rated as safe, comfortable, and comprehensible from bicycle riders’ perspectives. From a methods’ evaluation perspective, effects from the cycling simulator may be interpreted as behaviorally valid relatively between conditions only. Both methods offer a cost-effective approach to initially test infrastructure solutions by weeding out the less favorable ones in the early stages of the design.

mineral fertilizers, energy-saving technologies, working tool, uniformity of distribution, 3d, cad model, prototyping, experimental research, Engineering (General). Civil engineering (General), TA1-2040, Technology (General), and T1-995

Introduction. Improvement of the agro-industrial complex involves the creation of new and modernizations of existing working tools and machines. The important conditions for this are the application of modern technologies and ongoing cooperation with the actual manufacturing. The aim of the research is to develop an adaptive centrifugal working tool and improve the quality of mineral fertilization. Materials and Methods. The adaptive centrifugal working tool was developed and manufactured based on studying the state of the matter and requirements to machines for mineral fertilization. At all stages of the research, there were used computer-aided design and rapid prototyping methods based on additive technologies. Results. As a result of the use of the presented working tools, the machine operating width has increased by 10.0‒22.5%. Experimental working tools, in comparison with serial ones, allow decreasing uneven distribution of mineral fertilizers by 13.4% due to their redistribution from the central zone to the edges. Discussion and Conclusion. As a result of experimental studies, the efficiency of the developed adaptive centrifugal working tools has been proved. It allows increasing uniformity of mineral fertilizer distribution and the machine operating width. Modern design methods make it possible to considerably reduce time and costs.

UAVs, design, cyber-physical, prototyping, simulation, flight testing, Motor vehicles. Aeronautics. Astronautics, and TL1-4050

In this work, a cyber-physical prototyping and testing framework to enable the rapid development of UAVs is conceived and demonstrated. The UAV Development Framework is an extension of the typical iterative engineering design and development process, specifically applied to the rapid development of UAVs. Unlike other development frameworks in the literature, the presented framework allows for iteration throughout the entire development process from design to construction, using a mixture of simulated and real-life testing as well as cross-aircraft development. The framework presented includes low- and high-order methods and tools that can be applied to a broad range of fixed-wing UAVs and can either be combined and executed simultaneously or be executed sequentially. As part of this work, seven novel and enhanced methods and tools were developed that apply to fixed-wing UAVs in the areas of: flight testing, measurement, modeling and emulation, and optimization. A demonstration of the framework to quickly develop an unmanned aircraft for agricultural field surveillance is presented.

Physics and QC1-999

Diode-based nonlinear transmission lines (D-NLTL) are a class of pulse shaping networks capable of increasing the discrete spectral content of a pulse at high volumetric power density. However, a systematic design procedure for D-NLTLs is lacking, limiting their prototyping, evaluation, production, and adoption. To produce a D-NLTL design approach, parameters for UHF band (0.3–1 GHz) frequency generation are presented as a function of the input excitation pulse, network topology, and sub-components’ reactive value. Excitation pulse amplitude is found to have a strong effect on center frequency (fc), max frequency (fBragg), peak power (Ppeak), and RF power conversion efficiency (ηRF). In general, when cell inductance is decreased, both fc and signal propagation velocity are increased. The results are then presented as an example to design, build, test, and compare a 40-cell D-NLTL whose measured fc and fBragg are 256 and 446 MHz, respectively. Finally, we used the parameter space study results and empirical validation to present controllable waveform design rules-of-thumb.

AV shuttle, self-driving vehicle, language of driving, simulations, interaction, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999

Environmental awareness and technological advancements for self-driving cars are close to making autonomous vehicles (AV) a reality in everyday scenarios and a part of smart cities’ transportation systems. The perception of safety and trust towards AVs of passengers and other agents in the urban scenario, being pedestrians, cyclists, scooter drivers or car drivers, is of primary importance and the theme of investigation of many research groups. Driver-to-driver communication channels as much as car-to-driver human–machine interfaces (HMI) are well established and part of normal training and experience. The situation is different when users must cope with driverless and autonomous vehicles, both as passengers and as agents sharing the same urban domain. This research focuses on the new challenges of connected driverless vehicles, investigating an emerging topic, namely the language of driving (LoD) between these machines and humans participating in traffic scenarios. This work presents the results of a field study conducted at Tallinn University Technology campus with the ISEAUTO autonomous driving shuttle, including interviews with 176 subjects communicating using LoD. Furthermore, this study combines expert focus group interviews to build a joint base of needs and requirements for AVs in public spaces. Based on previous studies and questionnaire results, we established the hypotheses that we can enhance physical survey results using experimental scenarios with VR/AR tools to allow the fast prototyping of different external and internal HMIs, facilitating the assessment of communication efficacy, evaluation of usability, and impact on the users. The aim is to point out how we can enhance AV design and LoD communications using XR tools. The scenarios were chosen to be inclusive and support the needs of different demographics while at the same time determining the limitations of surveys and real-world experimental scenarios in LoD testing and design for future pilots.

desa unggulan, opensid, pelayanan administrasi, pelayanan desa, sistem informasi, Engineering (General). Civil engineering (General), TA1-2040, Science (General), and Q1-390

Administrasi kependudukan merupakan rangkaian kegiatan penataan dan penertiban dokumen dan data kependudukan serta pendayagunaan hasilnya untuk pelayanan publik dan pembangunan sektor lain. Desa Ngijo adalah salah satu desa unggulan yang ada di Kabupaten Malang. Kantor Desa Ngijo yang berada di Kabupaten Malang merupakan salah satu instansi pemerintah yang bergerak di bidang pelayanan masyarakat, namun dalam kinerja pelayanan masyarakat Balai Desa ini memiliki kendala dan permasalahan yaitu belum adanya ketersedian sistem informasi yang dapat menangani administrasi kependudukan. Desa Ngijo sebagai salah satu instansi pemerinatahan, memiliki peran yang penting yaitu sebagai pengelola data kependudukan di tingkat desa. Pengelolaan data kependudukan di Desa Ngijo saat ini masih belum memaksimalkan penggunaan teknologi informasi untuk pengelolaannya, sehingga masih terdapat beberapa kekurangan dan kendala yang dihadapi. Seperti masih terdapat kerangkapan data kependudukan, kesulitan dalam pencarian data, serta pembuatan laporan kependudukan. Sehingga pelayanan kepada masyarakat serta kerja dari perangkat desa menjadi kurang efektif dan efisien. Oleh karena itu dibutuhkan sebuah sistem informasi terkomputerisasi yang dapat digunakan untuk mengelola data tersebut. Metode yang digunakan untuk perancangan sistem administrasi kependudukan yaitu dengan metode prototyping. Dengan adanya sistem informasi administrasi kependudukan yang berbasiskan website ini, dapat memudahkan pengelolaan data kependudukan. Hal ini terwujud dalam persepsi dari 98% peserta pelatihan yang menyatakan bahwa sistem ini akan menjadi komponen layanan yang sangat bermanfaat bagi warga desa.

bird conservation, bird species identification, convolutional neural network, prototyping, Biology (General), and QH301-705.5

Abstract. Hermadi I, Wulandari, Dhira D. 2022. Development of a protected birds identification system using a convolutional neural network. Biodiversitas 23: 2561-2569. The protected animals are the animals having small populations, a sharp decline in the number of individuals in the wild, or endemic. The government has banned owning, keeping, or trading these animals. The first step in conserving these animals is identification. The government of the Republic of Indonesia has defined 564 species of bird as protected. This issue becomes a challenge to bird species identification. This study aims to develop a web application that implements a convolutional neural network (CNN) model for image-based protected bird species identification. This study uses the images of ten protected bird species in Indonesia as the research subject. This study consists of the stages viz. data collection, data preprocessing, data splitting, CNN model development, model evaluation, and web development using the Prototyping method. This study has successfully developed a model that gained 97% accuracy, 98% precision, and 97% recall on testing data. The study utilized HTML, CSS, Javascript, and Tensorflow.js for Web development. The black-box testing result shows that the prototype is acceptable.

left ventricular assist device, mechanical circulatory support, advanced heart failure, minimally invasive, axial-flow pump, Technology, Biology (General), and QH301-705.5

Despite evidence associating the use of mechanical circulatory support (MCS) devices with increased survival and quality of life in patients with advanced heart failure (HF), significant complications and high costs limit their clinical use. We aimed to design an innovative MCS device to address three important needs: low cost, minimally invasive implantation techniques, and low risk of infection. We used mathematical modeling to calculate the pump characteristics to deliver variable flows at different pump diameters, turbomachinery design software CFturbo (2020 R2.4 CFturbo GmbH, Dresden, Germany) to create the conceptual design of the pump, computational fluid dynamics analysis with Solidworks Flow Simulation to in silico test pump performance, Solidworks (Dassault Systèmes SolidWorks Corporation, Waltham, MA, USA) to further refine the design, 3D printing with polycarbonate filament for the initial prototype, and a stereolithography printer (Form 2, Formlabs, Somerville, MA, USA) for the second variant materialization. We present the concept, design, and early prototyping of a low-cost, minimally invasive, fully implantable in a subcutaneous pocket MCS device for long-term use and partial support in patients with advanced HF which unloads the left heart into the arterial system containing a rim-driven, hubless axial-flow pump and the wireless transmission of energy. We describe a low-cost, fully implantable, low-invasive, wireless power transmission left ventricular assist device that has the potential to address patients with advanced HF with higher impact, especially in developing countries. In vitro testing will provide input for further optimization of the device before proceeding to a completely functional prototype that can be implanted in animals.

lighting design, lighting control system, visual comfort, HDRi luminance analysis, LabVIEW, energy saving, Building construction, and TH1-9745

Lighting control systems (LCSs) play important roles in maintaining visual comfort and energy savings in buildings. This paper presents a prototype LCS using LabVIEW with real-time high dynamic range images and a digital multiplex controller to brighten lamps sequentially to provide visual comfort. The prototype is applied to a scaled classroom model with three schemes involving different activities and needs: writing and reading, requiring a uniform luminance of approximately 100 cd/m2, teaching using a whiteboard, requiring an illuminance of approximately 120 cd/m2 for the whiteboard and 60 cd/m2 for the desks, and drawing and art activities focused on the center of the room, requiring an illuminance of approximately 100 cd/m2 for the center area and 50 cd/m2 for the background area. For each scheme, two conditions are presented: one in which the room is treated as a closed room without windows, and the one in which the room has a large window on one wall that enables daylight to penetrate the room. The prototype works well with both schemes and provides different combinations of lamp brightness levels, starting from 10% to 60%, based on the activities and required luminance, and can save around 73–82% of electricity. The presence of daylight does not always result in more energy savings, as the brightness contrast for visual comfort needs to be considered.

assembly solution, automated connection, construction productivity, modular connection, modular buildings, plug-in device, Building construction, and TH1-9745

The prefabricated construction industry, also known as off-site construction, has been operating in North America for several years now and differs from traditional construction in its much shorter project timelines, lower costs, and increased build quality. However, the lack of a suitable and efficient assembly solution has been identified by many as a barrier to the use of off-site construction for larger buildings. To maximise the benefits of off-site manufacturing for multistorey buildings, an automated connection solution is presented in this paper. A new plug-in self-locking device was developed according to the following product design phases: on-site observations, definition of the problem and product specifications, solution generation, prototyping, fabrication, and testing. The plug-in self-locking device allows the assembly process to be accelerated by eliminating the fastening steps and a higher completion of modules off-site to be achieved. The design bears the compressive, tensile, and shear loads and contributes to the load path of the building.

split manufacturing, proximity attack, logic locking, and Technology

Split manufacturing was introduced as a countermeasure against hardware-level security threats such as IP piracy, overbuilding, and insertion of hardware Trojans. However, the security promise of split manufacturing has been challenged by various attacks which exploit the well-known working principles of design tools to infer the missing back-end-of-line (BEOL) interconnects. In this work, we define the security of split manufacturing formally and provide the associated proof, and we advocate accordingly for a novel, formally secure paradigm. Inspired by the notion of logic locking, we protect the front-end-of-line (FEOL) layout by embedding secret keys which are implemented through the BEOL in such a way that they become indecipherable to foundry-based attacks. At the same time, our technique is competitive with prior art in terms of layout overhead, especially for large-scale designs (ITC’99 benchmarks). Furthermore, another concern for split manufacturing is its practicality (despite successful prototyping). Therefore, we promote an alternative implementation strategy, based on package-level routing, which enables formally secure IP protection without splitting at all, and thus, without the need for a dedicated BEOL facility. We refer to this as “poor man’s split manufacturing” and we study the practicality of this approach by means of physical-design exploration.

Internet of Things, remote prototyping, FPGA devices, undergraduate teaching, digital design and synthesis lab, COVID-19 lockdowns, Electronics, and TK7800-8360

This paper presents a system for the remote design and testing of electronic circuits and devices with FPGAs during COVID-19 and similar lockdown periods when physical access to laboratories is not permitted. The system is based on the application of the IoT concept, in which the final device is a test board with an FPGA chip. The system allows for remote visual inspection of the board and the devices linked to it in the laboratory. The system was developed for remote learning taking place during the lockdown periods at Poznan University of Technology (PUT) in Poland. The functionality of the system is confirmed by two demonstration tasks (the use of the temperature and humidity DHT11 sensor and the design of a generator of sinusoidal waveforms) for students in the fundamentals of digital design and synthesis courses. The proposed solution allows, in part, to bypass the time-consuming simulations, and accelerate the process of prototyping digital circuits by remotely accessing the infrastructure of the microelectronics laboratory.

battery safety, electrical vehicles, socio-technical system, rapid prototyping, stakeholders, policy, and Technology

Battery technology is crucial in the transition towards electric mobility. Lithium-ion batteries are conquering the market but are facing fire safety risks that might threaten further applications. In this study, we address the problem and potential solutions for traction batteries in the European Union area. We do so by taking a unique socio-technical system perspective. Therefore, a novel, mixed-method approach is applied, combining literature review; stakeholder interviews; Failure Mode, Mechanisms, and Event Analysis (FMMEA); and rapid prototyping. Our findings confirm that fire safety is an upcoming concern. Still, most stakeholders lack a full understanding of the problem. Improving safety is a shared responsibility among supply chain and societal stakeholders. For automotive applications, voluntary standard-setting on safety risks is an appropriate tool to improve fire safety, whereas for niche applications, a top-down approach setting regulations seems more suited. For both groups, the adaptation of battery pack designs to prevent thermal runaway propagation is shown to be promising from a technological, practical, and organizational perspective. The chosen mixed-method approach allowed for a holistic analysis of the problems and potential solutions. As such, it can serve as an empowerment strategy for stakeholders in the field, stimulating further discussion, agenda building, and action.

Designbuild, Architectural Education, Material Experiences, Sociomateriality, Architectural Prototyping, Arts in general, and NX1-820

Most contemporary architecture programmes use a pedagogical model in which students construct their design knowledge by engaging in an architectural project. Due to the size and complexities of the physical environments they study, students develop their design knowledge primarily by using representations of the material world. The learning opportunities afforded by the experience of materials hence are often overlooked. In this study, we seek evidence that material experiences have an agency on architectural teaching and learning. Using sociomaterial perspectives, we followed two architecture designbuild courses, analysed their students’ learning diaries, and contextualised them with the teacher’s pedagogical reflections. We found correlations between specific materials and specific knowledge, skills, and technological competencies and demonstrated how materials could be used as ‘learning agents’ in architectural education. The paper’s findings contribute to the development of a material-driven ped­agogy in which materials are used as ‘learning agents’ in architectural education.

programmatic contents, competencies, content generating system, higher education, educational innovation, Education (General), and L7-991

This research combines the art of designing programmatic contents by competencies and the technological variable as an innovative resource in the context of higher education. The objective of this study was focused on the development of a technological system for the generation of programmatic contents by competencies in the curricular units of university careers. This research was carried out under the empirical approach; it is of an applicative type, since it generates a proposal and it was structured methodologically by phases: Phase I of approaching the manual system and user requirements was deployed under a field design in which the current situation and user expectations were described through the techniques of participant observation and meetings of experts in the area of educational technology (teaching staff of the different academic programs, heads of departments and coordinators of the Curriculum Commission), in order to carry out business rounds as a strategy of characterization and permanent consultation of the evolution of the system design to generate agreements. Phase II led to the establishment of the structural components of the prototype, and integrated the essentials from the systems theory, software engineering, and pedagogical didactic theories. Phase III was based on the methodology of system design by prototyping. As for the results, it was evidenced that the stakeholders considered feasible the use of the system to generate programmatic contents by competence, and finally the functionality of the system and the operational advantages for the generation of programmatic contents were demonstrated.

SimStack, workflows, Materials Design, Multiscale modelling, WaNos, and Technology

Establishing a fundamental understanding of the nature of materials via computational simulation approaches requires knowledge from different areas, including physics, materials science, chemistry, mechanical engineering, mathematics, and computer science. Accurate modeling of the characteristics of a particular system usually involves multiple scales and therefore requires the combination of methods from various fields into custom-tailored simulation workflows. The typical approach to developing patch-work solutions on a case-to-case basis requires extensive expertise in scripting, command-line execution, and knowledge of all methods and tools involved for data preparation, data transfer between modules, module execution, and analysis. Therefore multiscale simulations involving state-of-the-art methods suffer from limited scalability, reproducibility, and flexibility. In this work, we present the workflow framework SimStack that enables rapid prototyping of simulation workflows involving modules from various sources. In this platform, multiscale- and multimodule workflows for execution on remote computational resources are crafted via drag and drop, minimizing the required expertise and effort for workflow setup. By hiding the complexity of high-performance computations on remote resources and maximizing reproducibility, SimStack enables users from academia and industry to combine cutting-edge models into custom-tailored, scalable simulation solutions.

smart hydrogel, additive manufacturing, 4D printing, comparative analysis, Science, Chemistry, QD1-999, Inorganic chemistry, QD146-197, General. Including alchemy, and QD1-65

Hydrogel has become a commonly used material for 3D and 4D printing due to its favorable biocompatibility and low cost. Additive manufacturing, also known as 3D printing, was originally referred to as rapid prototyping manufacturing. Variable-feature rapid prototyping technology, also known as 4D printing, is a combination of materials, mathematics, and additives. This study constitutes a literature review to address hydrogel-based additive manufacturing technologies, introducing the characteristics of commonly used 3D printing hydrogel methods, such as direct ink writing, fused deposition modeling, and stereolithography. With this review, we also investigated the stimulus types, as well as the advantages and disadvantages of various stimulus-responsive hydrogels in smart hydrogels; non-responsive hydrogels; and various applications of additive manufacturing hydrogels, such as neural catheter preparation and drug delivery. The opportunities, challenges, and future prospects of hydrogel additive manufacturing technologies are discussed.

Teaching Materials, Writing a Drama Scripts, Local wisdom, Character Education, Education, Education (General), and L7-991

Students have difficulty in writing drama scripts. Teachers Indonesian are required to be able to develop teaching materials as a source of material information that is important for students to be skilled in writing drama scripts. Teaching materials developed by teachers should be charged with local wisdom and character education. This research aims to realize the learning materials of writing drama scripts loaded with local wisdom and character education. This research uses Research and Development (R&D) approach from Borg and Gall which is tailored to the needs of this research. This research and development resulted in teaching material writing drama scripts loaded with local wisdom and character education. As a learning material to write a drama script, the material contains six main parts: writing a drama script, intrinsic elements of drama, character education values, examples of local wisdom, examples of drama scripts that are charged with local wisdom and character education, and evaluations to measure students' competence. The procedure is divided into seven main stages, namely theoretical and practical analysis, analysis of the needs of students and teachers, prototyping, material expert tests, prototype revisions, product use tests, and product development of thinking-pair-sharing techniques writing drama scripts

requirements, negotiation, improvement, prototyping, Electronic computers. Computer science, and QA75.5-76.95

The Requirement Engineering phase, where all requests and software requirements of the user and the client are delivered, understood and agreed upon. However, often the developers are just too focused on implementing the software, even though the Requirements Engineering phase is a phase that can have a big impact. The impact is not only on the final product but also on the development process itself. In this study, the authors conducted software development negotiation of software requirements as a medium for stakeholders to negotiate the requirements of software products. In the negotiation system, the author will provide a means of decision support or group decision support system that a method of resolving conflicts. The main objectives of this work are twofold: 1) to assist the negotiation process between stakeholders and 2) to improvement quality software after negotiation. The workings of the E-Voting method are by giving choices to each sub-specification that has been chosen by stakeholders. We will select the choice that has the highest number of votes as a specification. We used prototyping as a method of developing a system life cycle because prototyping is very open to improvements that might occur after it releases the prototype version system. The results of evaluations show that the system has a high success rate based on 3 dimensions of testing, Performance (80.5%), Usability (78.5%), and User Satisfaction (78%).

blue-green infrastructure, prototyping, nature-based solutions, landscape architecture, greywater, integrated planning, and Agriculture

Blue-green architecture (BGA) describes buildings and open spaces that combine nature-based and technical systems of vegetation and urban water management. This creates positive effects on the urban climate, public health, biodiversity, and water balance. In this study, a design strategy for BGA is applied and evaluated on a practical project. The project consists of an interdisciplinary course in which students of architecture and landscape architecture designed and implemented a BGA for a school garden in Munich, Germany. The students worked in an interdisciplinary planning team in which they took on different roles and responsibilities (blue/green/integration). As a result, the design was put into practice by their own hands and a nature-based system was built. The greywater from the school garden is now treated in a constructed wetland and, in combination with rainwater, feeds into a redesigned pond. Biodiversity was increased and a contribution to the environmental education of the pupils was made. The students demonstrated high learning success. Finally, the design strategy for BGA was positively evaluated using a design-based research approach and additional points were added for future applications.

incremental forming, finite element simulation, biomedical implants, titanium, wall angle, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, and QC120-168.85

Advanced manufacturing techniques aimed at implants with high dependability, flexibility, and low manufacturing costs are crucial in meeting the growing demand for high-quality products such as biomedical implants. Incremental sheet forming is a promising flexible manufacturing approach for rapidly prototyping sheet metal components using low-cost tools. Titanium and its alloys are used to shape most biomedical implants because of their superior mechanical qualities, biocompatibility, low weight, and great structural strength. The poor formability of titanium sheets at room temperature, however, limits their widespread use. The goal of this research is to show that the gradual sheet formation of a titanium biomedical implant is possible. The possibility of creative and cost-effective concepts for the manufacture of such complicated shapes with significant wall angles is explored. A numerical simulation based on finite element modeling and a design process tailored for metal forming are used to complete the development. The mean of uniaxial tensile tests with a constant strain rate was used to study the flow behavior of the studied material. To forecast cracks, the obtained flow behavior was modeled using the behavior and failure models.

Maxillofacial reconstruction, Temporalis flap, Temporal hollowing, Computer-assisted surgery, Patient-specific implants, Rapid prototyping, Dentistry, RK1-715, Surgery, and RD1-811

Abstract Background Temporal hollowing is a common complication following the rotation of the temporalis muscle that leaves the patient with a cosmetic impairment. Several alloplastic materials have been used to reconstruct the donor site; however, these implants need meticulous adaptation to conform the periphery of the defect and restore the contour of the temporal area. The aim of this study was to assess the use of patient-specific polyetheretherketone (PEEK) temporal implants to prevent temporal hollowing following the use of full temporalis muscle flap for large maxillary defects reconstruction. Methods This was a prospective study conducted on eight patients with major maxillary defects indicating the need of reconstruction with full temporalis muscle flap or any lesion indicating major maxillary resection and immediate reconstruction with total temporalis muscle flap. For each patient, a patient-specific PEEK implant was fabricated using virtual planning and milled from PEEK blocks. In the surgical theater, the temporalis muscle was exposed, elevated, and transferred to the maxilla. After the temporalis muscle transfer, PEEK implants were fixed in place to prevent temporal hollowing. Results The surgical procedures were uneventful for all patients. The esthetic result was satisfactory with no post-operative complications except in one patient where seroma occurred after 2 weeks and resolved after serial aspiration. Conclusion Patient-specific PEEK implant appears to facilitate the surgical procedures eliminate several meticulous steps that are mainly based on the surgeon’s experience. Trial registration Clinical trials registration: NCT05240963 .

battery modelling, laser-structured electrodes, 3D battery concept, lithium-ion battery, multi-physics multi-domain modelling, virtual optimisation, Chemistry, and QD1-999

An electrochemical multi-scale model framework for the simulation of arbitrarily three-dimensional structured electrodes for lithium-ion batteries is presented. For the parameterisation, the electrodes are structured via laser ablation, and the model is fit to four different, experimentally electrochemically tested cells. The parameterised model is used to optimise the parameters of three different pattern designs, namely linear, gridwise, and pinhole geometries. The simulations are performed via a finite element implementation in two and three dimensions. The presented model is well suited to depict the experimental cells, and the virtual optimisation delivers optimal geometrical parameters for different C-rates based on the respective discharge capacities. These virtually optimised cells will help in the reduction of prototyping cost and speed up production process parameterisation.

additive manufacturing, powder bed fusion, high speed sintering, PET, Organic chemistry, and QD241-441

Laser Sintering (LS) was the first Powder Bed Fusion (PBF) method for polymers and it is now quite an established process for rapid prototyping and even for the production of functional parts. High Speed Sintering (HSS) is a variant of PBF which was later developed and it has the potential to be more scalable than LS. Most of the work for HSS and LS has been conducted with polyamide-12 (PA 12). This work reports the first effort to use polyethylene terephthalate (PET) in HSS. Well defined, simple and complex parts could be printed without any build failures. However, limitations were induced by current HSS machines which led to some curvature (warpage) in tensile bars after manufacturing. The reason for this was that all currently available machines for HSS are built for polymers such as polyamide 12, which means their maximum bed temperature is limited to 190 °C. This corresponds to the lower limit of processability of PET in PBF processes. The slightly curved tensile bars were straightened by heating them to 230 °C with a weight on top, and afterwards the mechanical properties were measured. The tensile modulus was similar to what was obtained with PET via LS but the strength and elongation-at-break (EAB) was lower. Microscopy showed that the reason for the lower strength and EAB was the incomplete melting of particles. This arose from the temperature limitation of the current generation of HSS machines. The porosity was established as 2.23% by helium pycnometry which is the same as for LS. The results of the thermal analysis indicated that the PET parts manufactured with HSS were semi-crystalline like the PET parts manufactured via LS.

three-dimensional (3D) bioprinting, sacrificial biomaterials, organ manufacturing, vascularization, Organic chemistry, and QD241-441

Additive manufacturing, also known as three-dimensional (3D) printing, relates to several rapid prototyping (RP) technologies, and has shown great potential in the manufacture of organoids and even complex bioartificial organs. A major challenge for 3D bioprinting complex org unit ans is the competitive requirements with respect to structural biomimeticability, material integrability, and functional manufacturability. Over the past several years, 3D bioprinting based on sacrificial templates has shown its unique advantages in building hierarchical vascular networks in complex organs. Sacrificial biomaterials as supporting structures have been used widely in the construction of tubular tissues. The advent of suspension printing has enabled the precise printing of some soft biomaterials (e.g., collagen and fibrinogen), which were previously considered unprintable singly with cells. In addition, the introduction of sacrificial biomaterials can improve the porosity of biomaterials, making the printed structures more favorable for cell proliferation, migration and connection. In this review, we mainly consider the latest developments and applications of 3D bioprinting based on the strategy of sacrificial biomaterials, discuss the basic principles of sacrificial templates, and look forward to the broad prospects of this approach for complex organ engineering or manufacturing.

design thinking, empathy, problem definition, product testing, prototyping, Business, and HF5001-6182

Entrepreneurial activities seek to fill the gaps created by the government’s inability to employ their citizens globally. However, design thinking, which is a human-centered and solution-based approach to problem-solving can enhance entrepreneurial success. This study investigates design thinking and business success in Nigeria. The purpose was to determine how design thinking influences business success using the five-stage model of design thinking as its framework. The study employed a quantitative methodology. The design was a cross-sectional survey of 224 out of 350 randomly selected online respondents that were invited. The respondents, who were either entrepreneurs or people with knowledge of entrepreneurial education at the undergraduate or postgraduate levels, were contacted through social media (Facebook and WhatsApp) and a structured questionnaire was used to elicit information from them. The data were analyzed using the structural equation modeling technique. Empathy, problem definition, ideation, prototyping, and product testing were found to be positively related to business success. However, while the positive relationships between empathy, problem definition, prototyping, and product testing were found to be significant at a 1% level, that of ideation was not significant at all; thus, empathy, problem definition, prototyping, and product testing are predictors of business success. Consequently, at a 99% confidence level, it is concluded that empathy, problem definition, prototyping, and product testing, and by implication, entrepreneurial design thinking, are significant predictors of business success.

PRISMA, CHIME, hybrid methods, biochemical and biophysical traits, Gaussian process regression, active learning, and Science

In preparation for new-generation imaging spectrometer missions and the accompanying unprecedented inflow of hyperspectral data, optimized models are needed to generate vegetation traits routinely. Hybrid models, combining radiative transfer models with machine learning algorithms, are preferred, however, dealing with spectral collinearity imposes an additional challenge. In this study, we analyzed two spectral dimensionality reduction methods: principal component analysis (PCA) and band ranking (BR), embedded in a hybrid workflow for the retrieval of specific leaf area (SLA), leaf area index (LAI), canopy water content (CWC), canopy chlorophyll content (CCC), the fraction of absorbed photosynthetic active radiation (FAPAR), and fractional vegetation cover (FVC). The SCOPE model was used to simulate training data sets, which were optimized with active learning. Gaussian process regression (GPR) algorithms were trained over the simulations to obtain trait-specific models. The inclusion of PCA and BR with 20 features led to the so-called GPR-20PCA and GPR-20BR models. The 20PCA models encompassed over 99.95% cumulative variance of the full spectral data, while the GPR-20BR models were based on the 20 most sensitive bands. Validation against in situ data obtained moderate to optimal results with normalized root mean squared error (NRMSE) from 13.9% (CWC) to 22.3% (CCC) for GPR-20PCA models, and NRMSE from 19.6% (CWC) to 29.1% (SLA) for GPR-20BR models. Overall, the GPR-20PCA slightly outperformed the GPR-20BR models for all six variables. To demonstrate mapping capabilities, both models were tested on a PRecursore IperSpettrale della Missione Applicativa (PRISMA) scene, spectrally resampled to Copernicus Hyperspectral Imaging Mission for the Environment (CHIME), over an agricultural test site (Jolanda di Savoia, Italy). The two strategies obtained plausible spatial patterns, and consistency between the two models was highest for FVC and LAI (R2=0.91, R2=0.86) and lowest for SLA mapping (R2=0.53). From these findings, we recommend implementing GPR-20PCA models as the most efficient strategy for the retrieval of multiple crop traits from hyperspectral data streams. Hence, this workflow will support and facilitate the preparations of traits retrieval models from the next-generation operational CHIME.

Fiber optics sensor, Soil water measurements, Distrubuite fiber optic sensors, Fiber Bragg Grating, Smart farming, Optics. Light, and QC350-467

Real time measurements of soil water content play a critical role in many fields of science as agronomy, geology, engineering, and hydrology. In the last years, agriculture has become one of the most important application fields of soil water sensors technology in order to optimize the irrigation process and to guarantee sustainable water resources management. This work provides a review on the latest emerging methodologies based on optical fiber sensing for soil moisture monitoring for agricultural and hydrological applications. In particular, the main studies referring to optical fiber sensors based on a variation of the refractive index of the external medium, sensors based on heated distributed temperature sensor (HDTS) and sensors based on Fiber Bragg Gratings (FBG) or Long Period Gratings (LPG) are here explored. Finally, some approaches based on the NIR absorbance spectroscopy are proposed for measuring the soil water content. Most of these approaches and technologies are still in a prototyping phase and only few of them are properly evaluated in situ real context.

Medicine and Science

Abstract The integration of smartphones and microfluidics is nowadays the best possible route to achieve effective point-of-need testing (PONT), a concept increasingly demanded in the fields of human health, agriculture, food safety, and environmental monitoring. Nevertheless, efforts are still required to integrally seize all the advantages of smartphones, as well as to share the developments in easily adoptable formats. For this purpose, here we present the free platform appuente that was designed for the easy integration of microfluidic chips, smartphones, and the cloud. It includes a mobile app for end users, which provides chip identification and tracking, guidance and control, processing, smart-imaging, result reporting and cloud and Internet of Things (IoT) integration. The platform also includes a web app for PONT developers, to easily customize their mobile apps and manage the data of administered tests. Three application examples were used to validate appuente: a dummy grayscale detector that mimics quantitative colorimetric tests, a root elongation assay for pesticide toxicity assessment, and a lateral flow immunoassay for leptospirosis detection. The platform openly offers fast prototyping of smartphone apps to the wide community of lab-on-a-chip developers, and also serves as a friendly framework for new techniques, IoT integration and further capabilities. Exploiting these advantages will certainly help to enlarge the use of PONT with real-time connectivity in the near future.

multi-axis, magnetic tactile sensor, robotic surgery, force range, Hall sensor, elastomer, Chemical technology, and TP1-1185

This paper presents a multi-axis low-cost soft magnetic tactile sensor with a high force range for force feedback in robotic surgical systems. The proposed sensor is designed to fully decouple the output response for normal, shear and angular forces. The proposed sensor is fabricated using rapid prototyping techniques and utilizes Neodymium magnets embedded in an elastomer over Hall sensors such that their displacement produces a voltage change that can be used to calculate the applied force. The initial spacing between the magnets and the Hall sensors is optimized to achieve a large displacement range using finite element method (FEM) simulations. The experimental characterization of the proposed sensor is performed for applied force in normal, shear and 45° angular direction. The force sensitivity of the proposed sensor in normal, shear and angular directions is 16 mV/N, 30 mV/N and 81 mV/N, respectively, with minimum mechanical crosstalk. The force range for the normal, shear and angular direction is obtained as 0–20 N, 0–3.5 N and 0–1.5 N, respectively. The proposed sensor shows a perfectly linear behavior and a low hysteresis error of 8.3%, making it suitable for tactile sensing and biomedical applications. The effect of the material properties of the elastomer on force ranges and sensitivity values of the proposed sensor is also discussed.

heterogeneous sensor networks, open-source, multi-modal, Internet of Things (IoT), SDK, modular API, Chemical technology, and TP1-1185

Sensor networks have dynamically expanded our ability to monitor and study the world. Their presence and need keep increasing, and new hardware configurations expand the range of physical stimuli that can be accurately recorded. Sensors are also no longer simply recording the data, they process it and transform into something useful before uploading to the cloud. However, building sensor networks is costly and very time consuming. It is difficult to build upon other people’s work and there are only a few open-source solutions for integrating different devices and sensing modalities. We introduce REIP, a Reconfigurable Environmental Intelligence Platform for fast sensor network prototyping. REIP’s first and most central tool, implemented in this work, is an open-source software framework, an SDK, with a flexible modular API for data collection and analysis using multiple sensing modalities. REIP is developed with the aim of being user-friendly, device-agnostic, and easily extensible, allowing for fast prototyping of heterogeneous sensor networks. Furthermore, our software framework is implemented in Python to reduce the entrance barrier for future contributions. We demonstrate the potential and versatility of REIP in real world applications, along with performance studies and benchmark REIP SDK against similar systems.

wearable antennas, textennas, garments, pattern software, fashion design software, integration, and Technology

A very large number of scientific papers have been published in the literature on wearable antennas of several types, structure and functionality. The main focus is always antenna efficiency from an engineering point of view. However, antenna integration into actual, realistic garments is seldom addressed. In this paper, 2D pattern and 3D virtual prototyping technology is utilized to develop regular clothing, available in the market, in which wearable antennas are incorporated in an automated manner, reducing the chances of compromising the garment elegance or comfort. The functionality of various commercial software modules is described, and particular design examples are implemented, proving the efficiency of the procedure and leading the way for more complex configurations.

autonomy, memristors, microrobots, simulation, time awareness, Computer engineering. Computer hardware, TK7885-7895, Control engineering systems. Automatic machinery (General), and TJ212-225

Micrometer‐scale robots capable of navigating enclosed spaces and remote locations are approaching reality. However, true autonomy remains an open challenge despite substantial progress made with externally supervised and manipulated systems. To accelerate the development of autonomous microrobots, alternatives to conventional top‐down lithography are sought. Such additive technologies like printing, coating, and colloidal self‐assembly allow for rapid prototyping and access to novel materials, such as polymers, bio‐ and nanomaterials. On the basis of recent experimental findings that memristive networks can be rapidly printed and lifted off as electronic microparticles, an alternative design paradigm is introduced based on arrays of two‐terminal memristive elements, which enables real‐time use of memory, sensing, and actuation in microrobots. Several memristor‐based designs are validated, each representing a key building block toward robotic autonomy: tracking elapsed time, timestamping a rare event, continuously cataloguing time‐indexed data, and accessing the collected information for a feedback‐controlled response as in a robotic glucose‐responsive insulin. The computational results establish an actionable framework for microrobotic design—tasks normally requiring complex circuits can now be achieved with self‐assembled and printed memristor arrays within microparticles.

3D printing, pre-operative planning, image processing, segmentation, Technology, Biology (General), and QH301-705.5

Patient-specific three-dimensional (3D) printed models have been increasingly used in many medical fields, including cardiac surgery for which they are used as planning and communication tools. To locate and plan the correct region of interest for the bypass placement during coronary artery bypass graft (CABG) surgery, cardiac surgeons can pre-operatively rely on different medical images. This article aims to present a workflow for the production of a patient-specific 3D-printed surgical guide, from data acquisition and image segmentation to final prototyping. The aim of this surgical guide is to help visualize the region of interest for bypass placement during the operation, through the use of dedicated surgical holes. The results showed the feasibility of this surgical guide in terms of design and fitting to the phantom. Further studies are needed to assess material biocompatibility and technical properties.

mycelium, architecture, structural design, computational design, digital fabrication, additive manufacturing, and Technology

In an increasing effort to address the environmental challenges caused by the currently linear economic paradigm of “produce, use, and discard”, the construction industry has been shifting towards a more circular model. A circular economy requires closing of the loops, where the end-of-life of a building is considered more carefully, and waste is used as a resource. In comparison to traditional building materials such as timber, steel and concrete, mycelium-based materials are renewable alternatives that use organic agricultural and industrial waste as a key ingredient for production, and do not rely on mass extraction or exploitation of valuable finite or non-finite resources. Mycelium-based materials have shown their potential as a more circular and economically competitive alternative to conventional synthetic materials in numerous industries ranging from packaging, electronic prototyping, furniture, fashion to architecture. However, application of mycelium-based materials in the construction industry has been limited to small-scale prototypes and architectural installations due to low mechanical properties, lack of standardisation in production methods and material characterisation. This paper aims to review the current state of the art in research and applications of mycelium-based materials across disciplines, with a particular focus on digital methods of fabrication, production, and design. The information gathered from this review will be synthesised to identify key challenges in scaling up applications of mycelium-based materials as load-bearing structural elements in architecture and suggest opportunities and directions for future research.

lab-on-a-chip, lab-on-a-foil, wax valve, microfluidic ELISA, Biotechnology, and TP248.13-248.65

Lab-on-a-chip devices incorporating valves and pumps can perform complex assays involving multiple reagents. However, the instruments used to drive these chips are complex and bulky. In this article, a new wax valve design that uses light from a light emitting diode (LED) for both opening and closing is reported. The valves and a pumping chamber are integrated in lab-on-a-foil chips that can be fabricated at low cost using rapid prototyping techniques. A chip for the implementation of enzyme-linked immunosorbent assays (ELISA) is designed. A porous nitrocellulose material is used for the immobilization of capture antibodies in the microchannel. A compact generic instrument with an array of 64 LEDs, a linear actuator to drive the pumping chamber, and absorbance detection for a colorimetric readout of the assay is also presented. Characterization of all the components and functionalities of the platform and the designed chip demonstrate their potential for assay automation.

electric bicycle, innovation, market, concept, architecture, QFD, Technology, Engineering design, and TA174

The following case study portrays the several steps required to conceive a product from scratch. The first step involves an in-depth analysis of today’s electric bicycle market in order to obtain data and information relating to the levels of innovation and comfort required by customers. Then, we evaluate the implementation of a useful method to understand the level of innovation that the product must have to be competitive on the market. The second part studies the architecture of the product, considering the different components already sold on the market which will become part of the project. The third part concerns a comparison between different stylistic trends that the vehicle may have (in order to outline the best one). The fourth part concerns the CAD realization of the virtual model complete with all its parts, including a structural verification study of the frame. The last part studies the presentation of the product to the customer, exploring different effective ways to communicate what the strengths of the new product will be (also allowing them to customize it before its realization). The plan for the realization of the new product, starting from the concept to arrive at the final presentation to the customer, follows the methods proposed by applying a series of steps to develop a generic new product in an efficient, sensible, and methodical manner. Therefore, we will refer to quality function deployment (QFD), benchmarking (BM), design for X, until reaching the final prototyping and testing phases.

FPGA, rapid prototyping, Simulink, HDL Coder, Xilinx Zynq, Zedboard, Electronics, and TK7800-8360

Many advanced power electronics control techniques present a steep computational load, demanding advanced controllers, such as FPGAs. However, FPGA development is a daunting and time-consuming task, inaccessible to most users. This paper proposes a complete methodology for prototyping power electronics with Xilinx Zynq-based boards using Matlab/Simulink and HDL Coder. Even though these tools are relatively well documented, and several works in the literature have used them, a methodology for developing power electronics systems with them has never been proposed. This paper aims to address that, by proposing a complete programming and design methodology for Zynq-based power electronics and discussing important drawbacks and hurdles in Simulink/HDL Coder development, as well as their possible solutions. In addition, techniques for the implementation of all required peripherals (ADCs, digital outputs, etc.), system protections, and real-time data acquisition on Zynq boards are presented. This methodology considerably reduces the development time and effort of power electronics solutions using Zynq-based boards. In addition, a demonstration Simulink model is provided with all proposed techniques and protections, for use with a readily available development board (Zedboard) and ADC modules. This should further reduce the learning curve and development effort of this type of solution, contributing to a broader access to high-performance control prototyping using Zynq-based platforms. An application example is presented to demonstrate the potential of the proposed workflow, using a Zedboard to control a multilevel UPS inverter prototype with Model Predictive Control.

multi-principal element alloys, directed energy deposition, laser metal deposition, grains, crack formation, melt pool, and Technology

As efforts associated with the exploration of multi-principal element alloys (MPEAs) using computational and data-intensive methods continue to rise, experimental realization and validation of the predicted material properties require high-throughput and combinatorial synthesis of these alloys. While additive manufacturing (AM) has emerged as the leading pathway to address these challenges and for rapid prototyping through part fabrication, extensive research on developing and understanding the process-structure-property correlations is imminent. In particular, directed energy deposition (DED) based AM of MPEAs holds great promise because of the boundless compositional variations possible for functionally graded component manufacturing as well as surface cladding. We analyze the recent efforts in DED of MPEAs, the microstructural evolution during the laser metal deposition of various transition and refractory elements, and assess the effects of various processing parameters on the material phase and properties. Our efforts suggest that the development of robust predictive approaches for process parameter selection and modifying the synthesis mechanisms are essential to enable DED platforms to repeatedly produce defect free, stable and designer MPEAs.

on-farm experiment, collective learning, participatory research, basket of options, farmers' criteria, farming system typology, Nutrition. Foods and food supply, TX341-641, Food processing and manufacture, and TP368-456

Designing innovative cropping systems is an active field of agricultural research challenged by the agroecological transition. One of the challenges is to adapt cropping systems to the diversity of farms and contexts. For instance, in the cotton production zone of Burkina Faso differences between farm resources, agricultural situations and agronomic constraints have resulted in a wide range of farming systems. In this context, to break with the trend toward cotton production, we co-designed eight legume-based innovative cropping systems (ICS) likely to meet the objectives sought and the constraints faced by a wide range of local farmers, thus constituting a “basket of options”. Our approach was to enable each farmer to choose the option they considered best suited to their conditions. To that end, the ICSs were implemented and discussed with farmers in participatory prototyping trials. After one season of co-evaluating the different ICSs, the farmers taking part in the co-evaluation were able to test an ICS on their own farm, by choosing and adapting one of the options. Thirty-nine farmers out of seventy-three chose an ICS to test. They were asked the reasons for their choice. Their selection criteria were analyzed in relation to comments made during collective activities organized in the participatory prototyping trials. To complete this analysis, we built an expert-based farming system typology and a statistical typology based on data collected in a rural household multi-indicator survey (RHoMIS) of 63 farms participating in this study. The two farming system typologies were compared, and the relationships between farming system types and the ICS tested on the farm were analyzed. We found that farmers did not really base their choice on their farming system. Rather, they used a wide range of criteria that varied from farmer to farmer, and they were influenced by what they had learned during the collective activities organized in the participatory prototyping trials.

Vibration isolation, Sensitive experiments, Spring-damper, Prototyping, Science (General), and Q1-390

Mechanical vibrations greatly influence sensitive instruments and experiments, yet they are unavoidable. Commercial solutions that mitigate the transfer of mechanical vibrations into experiments and instruments are often associated with high prices and big footprints and are not readily available for low investment explorative testing, experimenting, and prototyping. In this paper, an open-source design for a vibration isolation chamber is presented that is constructed from readily available components and hardware such as off-the-shelf furniture and honey. An extensive guide on how to construct the simple spring-damper-based passive vibration isolation chamber is presented, and its performance is validated using a high-precision seismic accelerometer. The vibration isolation system consists of steel springs and dashpots made of steel spheres suspended in high viscosity honey. The system resonates at 1.2 Hz and successfully mitigates the transfer of vibrations of frequencies determined to be of critical interest in the 5–20 Hz range. The well-performing system has proven to be an invaluable asset in the laboratory toolbox when sensitive experiments are carried out and has already been used in a multitude of projects. The design is shared so that others may also benefit from this tool.

3D printing, Anaerobic, Probiotics, In vitro dissolution model, Oral drug delivery, Rapid prototyping, Science (General), and Q1-390

In vitro release and dissolution models are widely used in the development phases of oral drug delivery systems to measure how an active pharmaceutical ingredient (API) is released from a dosage form. However, additional requirements for these models arise when evaluating probiotic dosage forms since they are often sensitive to temperature and oxygen levels. As a solution to this, we propose a custom-designed anaerobic in vitro release setup, made mainly by 3D printing and laser cutting, to function together with state-of-the-art pharmaceutical dissolution equipment – in this case, a microDISS Profiler™. The in vitro release model makes it possible to study the release rate of oxygen-sensitive probiotics in simulated intestinal conditions, while ensuring their survival due to the anaerobic conditions. This has not been possible so far since the available in vitro dissolution models have not been compatible with anaerobic conditions. With two different case studies, the developed model combined with a microDISS Profiler™ has proven capable of measuring the release of a probiotic and a small-molecule API from microdevices for oral drug delivery. Further, the model facilitated the survival of anaerobic bacteria present in the release medium.

Ultraviolet germicidal irradiation (UVGI) lights, Indoor air quality (IAQ), Dehumidification, Reduce fungi, Science (General), and Q1-390

Many New Zealand residential dwellings suffer from dampness and fungi during the winter, which can cause respiratory health problems. This can be due to poor insulation and ventilation, and the situation worsens when residents cannot afford to heat the dwelling. The main aim of this paper is to modify an existing dehumidifier so that it can remove moisture, heat the living space and reduce fungi growth and bacteria. To achieve that, we installed ultraviolet germicidal lights (UVGI) in an existing dehumidifier with a total cost of USD $150.7 (NZD $213.76). The UVGI lights are known to be efficient in destroying the DNA of fungi and bacteria. The results show that the device reduced the fungi growth and did increase the room temperature because the dehumidifier captured two litres of water over 24 h of testing. The proposed device did achieve a reduction in particulate matters, from 0.9 μg/m3 to 0.14 μg/m3 and an acceptable range of relative humidity below 50%, which reduces the favourable conditions for fungi growth. Therefore, our proposed low-cost device does improve the indoor air quality (IAQ) in the living space.

autonomous driving, simulators, reinforcement learning, Information technology, and T58.5-58.64

Autonomous driving is a research field that has received attention in recent years, with increasing applications of reinforcement learning (RL) algorithms. It is impractical to train an autonomous vehicle thoroughly in the physical space, i.e., the so-called ’real world’; therefore, simulators are used in almost all training of autonomous driving algorithms. There are numerous autonomous driving simulators, very few of which are specifically targeted at RL. RL-based cars are challenging due to the variety of reward functions available. There is a lack of simulators addressing many central RL research tasks within autonomous driving, such as scene understanding, localization and mapping, planning and driving policies, and control, which have diverse requirements and goals. It is, therefore, challenging to prototype new RL projects with different simulators, especially when there is a need to examine several reward functions at once. This paper introduces a modified simulator based on the Udacity simulator, made for autonomous cars using RL. It creates reward functions, along with sensors to create a baseline implementation for RL-based vehicles. The modified simulator also resets the vehicle when it gets stuck or is in a non-terminating loop, making it more reliable. Overall, the paper seeks to make the prototyping of new systems simple, with the testing of different RL-based systems.

industrial design structure (IDeS), quality function deployment (QFD), benchmarking (BM), Top-Flop analysis (TFA), stylistic design engineering (SDE), suburban mobility, Engineering machinery, tools, and implements, TA213-215, Technological innovations. Automation, and HD45-45.2

The present study was set to validate two different suburban-type sportscar bodies with shared common underpinnings. The chosen method to develop this project was the Industrial Design Structure (IDeS), which characterizes the ability to use the different innovative techniques known within the industrial field, across the whole organization. This method is embodied by following a series of structured analysis tools, such as QFD (Quality Function Deployment), Benchmarking (BM), Top-Flop analysis (TFA), Stylistic Design Engineering (SDE), Prototyping, Testing, Budgeting and Planning. This project aims to study the present-day car market and to foresee deployment in the near future. This attempt was confirmed by delivering the complete styling and technical feasibility characteristics of two different sports cars, obtained by the IDeS methodology. This approach of embodying design together with phases of product development would provide a better engineered, target-oriented product, that uses state-of-the-art style and CAD environments to reduce product development time and, hence, overall Time to Market (TTM).

Service composition, Semantic web services, RDF, OpenAPI Specification, Semantic ontology, Computer engineering. Computer hardware, TK7885-7895, Information technology, T58.5-58.64, Electronic computers. Computer science, and QA75.5-76.95

Abstract Web services are provided with documents that at the very least specify the endpoint, input parameters, and output or response of each operation to expose their capabilities. This should be considered through an understandable format for humans and/or machines. In the Representational State Transfer (REST) architectural style, the OpenAPI Specification (OAS) is used as a reference to create web service descriptions. However, it only supports syntactic interoperability, leading to the incapability of supporting the automated selection process. To overcome this, OAS documents must be enhanced by including semantics to each resource to provide “understandable” services. Therefore, this study aims to develop a system capable of transforming resources in OAS documents into RDF-based semantic web services. To begin, a relational database schema based on the OAS structure is created to store all objects in the OAS document. The published open-linked vocabulary was then used to create the ontology, which maps resources and their relationships on the RDF data model. To build RDF-based semantic web services, R2RML was used to generate the relational database model into triple RDF. The proposed system was also tested through prototyping and using a dataset of 106 OAS documents, which were downloaded from APIs.guru between 5–10 May 2021. The number of triple RDFs generated per document varied with resource rate. An OAS document generates 36 to 16,505 triple RDF in a dataset. The end product was a triple RDF knowledge base maintained by a graph management database. It is now possible to find service operations, input and output parameters, and service composition requirements utilizing the repository semantic web services using SPARQL. On the other hand, the use of relational databases to store OAS resources increased reuse efficiency by approximately 48%, owing to service developers designing interoperability between uniform parameter services, which were then used as input and output.

core–shell nanoparticles, stacking, molecular dynamics simulation, sintering behavior, Technology, and Science

Selective laser sintering (SLS) is one of the most commonly used methods in additive manufacturing, due to its high prototyping speed and applicability to various materials. In the present work, molecular dynamics (MD) simulations were performed to study the thermodynamic behaviors of the planar stacked nanoparticles (NPs) model and explore the potential capability of the SLS process with nano-sized metal powders in the zero-gravity space environment. A multi-particle model of titanium–aluminum (Ti–Al) core–shell NP with a particle radius of 50 Å was constructed to investigate the characteristics of the melted pattern during sintering. Two patterns with different spatial densities were considered to study the influence of particle stacking on the melting process. Various core volume fractions and heating rates were examined to investigate their effects on the quality of the final sintered product. The stacked-NPs models with core volume fractions (CVFs) of 3%, 12%, and 30% were linearly heated up to 1100 K from room temperature (298 K) with heating rates of 0.04, 0.2, 0.5, and 1.0 K ps−1. The initial fusion temperature and final sintering temperature for each stacking pattern were obtained via the validation from the radial distribution function, mean squared displacement, and the radius of the gyration analysis. The 30% CVF yields the largest neck size before the melting point, while beyond the melting point, a larger core helps delay the formation of the fully-melted products. It is observed that using the close-packed stacked-NPs model under a slow heating rate (long melting duration) would help form a stable, completely sintered product with a relatively low final sintering temperature.

Fused deposition modeling (FDM), Fiber bragg-grating (FBG) sensor, Earth pressure, Water pressure, Engineering geology. Rock mechanics. Soil mechanics. Underground construction, and TA703-712

A novel fiber Bragg grating (FBG) sensor with three-dimensional (3D) fused deposition modeling (FDM) approach is proposed for effective stress measurement in soil mass. The three-diaphragm structure design is developed to measure earth and water pressures simultaneously. The proposed transducer has advantages of small size, high sensitivity, low cost, immunity to electromagnetic interference and rapid prototyping. The working principle, design parameters, and manufacturing details are discussed. The proposed transducer was calibrated for earth and water pressures measurement by using weights and a specially designed pressure chamber, respectively. The calibration results showed that the wavelength of the transducer was proportional to the applied pressure. The sensitivity coefficients of the earth and water pressures were 12.633 nm/MPa and 6.282 nm/MPa, respectively. Repeated tests and error analysis demonstrated the excellent stability and accuracy of the earth and water pressure measurements. The performance of the proposed transducer was further verified by a model experimental test and numerical analysis, which indicated that the proposed transducer has great potential for practical applications.

gear system, vibration control, vibration absorber, internal resonance, Mechanical engineering and machinery, and TJ1-1570

The gear system is one of the most widely-used transmission systems due to its accurate transmission ratio and high efficiency. However, torsional vibration may severely degrade transmission performance and shorten the gear lifespan. In view of this, a nonlinear interaction principle suitable for vibration energy transfer is researched, and an internal resonance based method is put forward to reduce the torsional vibration of the gear system. According to the coupling relationship between the gear torsional vibration mode and the vibration absorber mode, the 1:1 internal resonance condition is analyzed by the multiple scale method and the sufficient and necessary conditions for establishing internal resonance are obtained. Through stability analysis, the vibration energy transfer channel based on internal resonance is successfully established, by which vibration energy can be transferred to and dissipated by the vibration absorber. Based on numerical and virtual prototyping simulations, vibration reduction performances are examined, including effectiveness, damping characteristics and robustness. The research results show that the proposed internal resonance based method can effectively reduce the torsional vibration of the gear system.

flexible manipulator, primary resonance, saturation control, Mechanical engineering and machinery, and TJ1-1570

When primary resonance occurs, even a small external disturbance can abruptly excite large amplitude vibration and deteriorate the working performance of a flexible manipulator. Most active control methods are effective for non-resonant vibration but not for primary resonance. In view of this, this paper puts forward a new nonlinear saturation-based control method to suppress the primary resonance of a flexible manipulator considering complicated rigid-flexible coupling and modal coupling. A vibration absorber with variable stiffness/damping is designed to establish an energy exchange channel for saturation. A novel idea of modal coupling enhancement is suggested to improve saturation performance by strengthening the coupling relationship between the mode of the vibration absorber and the controlled mode of the flexible manipulator. Through stability analysis on the primary resonance response of the flexible manipulator with the vibration absorber, the saturation mechanism is successfully established and the effectiveness of the saturation control algorithm is validated. On this basis, several important indexes are extracted and employed to optimize saturation control. Finally, a series of virtual prototyping simulations and experiments are conducted to verify the feasibility of the suggested saturation-based control method. This research will contribute to the primary resonance suppression of a flexible manipulator under a complex external excitation environment.

integrated optics, photonic chips, femtosecond laser fabrication, optical communications, Mechanical engineering and machinery, and TJ1-1570

Integrated optics, having the unique properties of small size, low loss, high integration, and high scalability, is attracting considerable attention and has found many applications in optical communications, fulfilling the requirements for the ever-growing information rate and complexity in modern optical communication systems. Femtosecond laser fabrication is an acknowledged technique for producing integrated photonic devices with unique features, such as three-dimensional fabrication geometry, rapid prototyping, and single-step fabrication. Thus, plenty of femtosecond laser-fabricated on-chip devices have been manufactured to realize various optical communication functions, such as laser generation, laser amplification, laser modulation, frequency conversion, multi-dimensional multiplexing, and photonic wire bonding. In this paper, we review some of the most relevant research progress in femtosecond laser-fabricated photonic chips for optical communications, which may break new ground in this area. First, the basic principle of femtosecond laser fabrication and different types of laser-inscribed waveguides are briefly introduced. The devices are organized into two categories: active devices and passive devices. In the former category, waveguide lasers, amplifiers, electric-optic modulators, and frequency converters are reviewed, while in the latter, polarization multiplexers, mode multiplexers, and fan-in/fan-out devices are discussed. Later, photonic wire bonding is also introduced. Finally, conclusions and prospects in this field are also discussed.

additive manufacturing, 3D-Printing, rapid prototyping, FFF, SSE, personalized therapy, Organic chemistry, and QD241-441

Novel additive manufacturing (AM) techniques and particularly 3D printing (3DP) have achieved a decade of success in pharmaceutical and biomedical fields. Highly innovative personalized therapeutical solutions may be designed and manufactured through a layer-by-layer approach starting from a digital model realized according to the needs of a specific patient or a patient group. The combination of patient-tailored drug dose, dosage, or diagnostic form (shape and size) and drug release adjustment has the potential to ensure the optimal patient therapy. Among the different 3D printing techniques, extrusion-based technologies, such as fused filament fabrication (FFF) and semi solid extrusion (SSE), are the most investigated for their high versatility, precision, feasibility, and cheapness. This review provides an overview on different 3DP techniques to produce personalized drug delivery systems and medical devices, highlighting, for each method, the critical printing process parameters, the main starting materials, as well as advantages and limitations. Furthermore, the recent developments of fused filament fabrication and semi solid extrusion 3DP are discussed. In this regard, the current state of the art, based on a detailed literature survey of the different 3D products printed via extrusion-based techniques, envisioning future directions in the clinical applications and diffusion of such systems, is summarized.

3D printing, polymer texture printing, polymer morphology, crystal orientation, mechanical properties, Organic chemistry, and QD241-441

Direct digital manufacturing consists of a set of techniques that enable products to be fabricated directly from their digital definition, without the use of complex tooling or moulds. This manufacturing approach streamlines prototyping and small-scale production, as well as the mass customization of parts with complex designs immediately fixed before fabrication. With broad applicability, there are clearly opportunities in the field of medical devices for its use. However, many of the developments of direct digital manufacturing focus on simply specifying the shape or the form of the product, and this limited scope throws away many of the particular advantages of direct digital manufacturing. This work is focused on remedying this situation so that the digital specification of the fabricated product includes the properties as well as the form of the product. We use in situ time-resolving small-angle X-ray scattering measurements performed at the ALBA Synchrotron Light Source in Barcelona to evaluate the control that can be exerted on the morphology of a semi-crystalline polymer during extruder-based 3D printing. We use this as a methodology for printing the patterns of the morphology of the polymer to realise the patterns of properties of the polymeric material, specifically the modulus of the polymer. We give an example of products produced in this manner that contain spatial variation in their properties.

snake robot, series elastic actuator, SEA, robotics, Mechanical engineering and machinery, and TJ1-1570

The term perception-driven obstacle-aided locomotion (POAL) was proposed to describe locomotion in which a snake robot leverages a sensory-perceptual system to exploit the surrounding operational environment and to identify walls, obstacles, or other structures as a means of propulsion. To attain POAL from a control standpoint, the accurate identification of push-points and reliable determination of feasible contact reaction forces are required. This is difficult to achieve with rigidly actuated robots because of the lack of compliance. As a possible solution to this challenge, our research group recently presented Serpens, a low-cost, open-source, and highly compliant multi-purpose modular snake robot with a series elastic actuator (SEA). In this paper, we propose a new prototyping iteration for our snake robot to achieve a more dependable design. The following three contributions are outlined in this work as a whole: the remodelling of the elastic joint with the addition of a damper element; a refreshed design for the screw-less assembly mechanism that can now withstand higher transverse forces; the re-design of the joint module with an improved reorganisation of the internal hardware components to facilitate heat dissipation and to accommodate a larger battery with easier access. The Robot Operating System (ROS) serves as the foundation for the software architecture. The possibility of applying machine learning approaches is considered. The results of preliminary simulations are provided.