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Traveling wave structures for lossless ion manipulation (TW-SLIM) has proven a valuable tool for the separation and study of gas-phase ions. Unfortunately, many of the traditional components of TW-SLIM experiments manifest practical and financial barriers to the technique's broad implementation. To this end, a series of technological innovations and methodologies are presented which enable for simplified SLIM experimentation and more rapid TW-SLIM prototyping. In addition to the use of multiple independent board sets that comprise the present SLIM system, we introduce a low-cost, multifunctional traveling wave generator to produce TW within the TW-SLIM. This square-wave producing unit proved effective in realizing TW-SLIM separations compared to traditional approaches. Maintaining a focus on lowering barriers to implementation, the present set of experiments explores the use of on-board injection (OBI) methods, which offer potential alternatives to ion funnel traps. These OBI techniques proved feasible and the ability of this simplified TW-SLIM platform to enhance ion accumulation was established. Further experimentation regarding ion accumulation revealed a complexity to ion accumulation within TW-SLIM that has yet to be expounded upon. Lastly, the ability of the presented TW-SLIM platform to store ions for extended periods (1 s) without significant loss (<10%) was demonstrated. The aforementioned experiments clearly establish the efficacy of a simplified TW-SLIM platform which promises to expand adoption and experimentation of the technique.
(Copyright © 2022 Elsevier B.V. All rights reserved.)

Electromagnetic Phenomena, Phantoms, Imaging, Prostheses and Implants, and Wireless Technology

Objective: Computational modeling is increasingly used to design charging systems for implanted medical devices. The design of these systems must often satisfy conflicting requirements, such as charging speed, specific absorption rate (SAR) and coil size. Fast electromagnetic solvers are pivotal for enabling multi-criteria optimization. In this paper, we present an analytical model based on the quasi-static approximation as a fast, yet sufficiently accurate tool for optimizing inductive charging systems.
Methods: The approximate model was benchmarked against full-wave simulations to validate accuracy and improvement in computation time. The coupling factor of two test coils was measured for lateral and axial displacements and the SAR was measured experimentally in a PAA phantom.
Results: The approximate model takes only 11 seconds to compute a single iteration, while the full-wave model takes 5 hours to compute the same case. The maximum difference with full-wave simulations was less than 24% and the mean difference less than 2%. Adding a novel figure of merit into the multi-criterion optimization resulted in a 16% higher charging speed. The measured results of the SAR and coupling factor are within a 5 mm coil offset margin.
Conclusion: The proposed approximate model succeeds as a rapid prototyping tool, enabling fast and sufficiently accurate optimization for wireless charging systems.
Significance: The approximate model is the first of its kind to compute both the coupling factor and the SAR near conducting structures fast enough to enable optimization of charging speed.

The use of personal protective equipment (PPE) has become essential to reduce the transmission of coronavirus disease 2019 (COVID-19) as it prevents the direct contact of body fluid aerosols expelled from carriers. However, many countries have reported critical supply shortages due to the spike in demand during the outbreak in 2020. One potential solution to ease pressure on conventional supply chains is the local fabrication of PPE, particularly face shields, due to their simplistic design. The purpose of this paper is to provide a research protocol and cost implications for the rapid development and manufacturing of face shields by individuals or companies with minimal equipment and materials. This article describes a best practice case study in which the establishment of a local manufacturing hub resulted in the swift production of 12,000 face shields over a seven-week period to meet PPE shortages in the North-West region of Ireland. Protocols and processes for the design, materials sourcing, prototyping, manufacturing, and distribution of face shields are described. Three types of face shields were designed and manufactured, including Flat, Laser-cut, and 3D-printed models. Of the models tested, the Flat model proved the most cost-effective (€0.51/unit), while the Laser-cut model was the most productive (245 units/day). The insights obtained from this study demonstrate the capacity for local voluntary workforces to be quickly mobilised in response to a healthcare emergency, such as the COVID-19 pandemic.
(© 2022 The Authors.)

Electromagnetic fields, Antennas (Electronics), Wireless sensor networks, and Rapid prototyping

Keywords: metallization; radio frequency performance; SLA reflector; three-dimensional printed Abstract A novel high precision and lightweight reflector antenna is proposed. The fabrication process of the reflector adopted Stereo Lithography Apparatus (SLA) printed and metallization. The proposed SLA Reflector (SLAR) antenna structure adopts three-dimensional-printed, which can design complex geometric shapes flexibly and rapid prototyping. That is a good substitute for the traditional method of millimeter wave reflector processing. In order to realize radio frequency (RF) characteristics perfectly, the metallization process of photosensitive resin was elaborated, which realized by first electroless nickel plating, then copper electroplating, and finally chromium electroplating on the protective layer. For verification, the designed reflector antenna was manufactured and measured. The reflectivity of SLAR was measured well by the bow method, which validates excellent fabrication accuracy and reliability. The gain and pattern were measured in the anechoic chamber. The results show that the proposed reflector antenna achieves the gain of 25dBi and the 3dB gain bandwidth of 43% over the full Ka-band. A good agreement can be observed between measurement and simulation. Biographical information: Liwei Guo received the B.E. degree in from the Guilin University of Electronic Technology, Guilin, China in 2006. She is currently pursuing the PhD degree in Guilin University of Electronic Technology, Guilin, China. Her current research interests include metasurfaces, millimeter-wave reflector antenna. Simin Li received the B.S. degree in wireless communication engineering from Nanjing University of Posts and Telecommunications, Nanjing, China, in 1984, and the M.S. and PhD degrees in electronics engineering from the University of Electronic Science and Technology of China, Chengdu, China, in 1989 and 2007, respectively. Dr. Li is currently the President and a Professor with Guangxi University of Science and Technology, Liuzhou, China. His current research interests include the design of electrically small antennas, antenna arrays for high-frequency communication systems, and wireless sensor networks. Xing Jiang received the Master's degree in electromagnetic field and microwave technology from Beijing Institute of Technology, Beijing, China, in 1986. Since 2000, she has been a Professor with the Guilin University of Electronic Technology, Guilin, China. She was sponsored by the National Natural Science Foundation of China and the Natural Science Foundation of Guangxi. Her research interests include smart communication system design, conformal antenna array, and bioelectromagnetics. Xin Liao received the B.E. degree from Chongqing University of Posts and Telecommunications, Chongqing, China, in 1990. He is currently a Lecturer with the Guilin University of Electronic Technology, Guilin, China. His research interests include Electromagnetic Compatibility and antenna measurement. Ying Zhang received the B.E. degree in Harbin Institute of Technology of optical instrument. Now she is a researcher at Beijing Simulation Center. Her research interest is the simulation of visible light/infrared guidance and control systems. Bin Shi is an associate researcher- in Beijing Simulation Center. Her research interest is the simulation of radio frequency target accuracy. Article Note: Funding information Guangxi Innovation Driven Development Special Fund Project, Grant/Award Number: GUIKEAA19254012; Innovation Project of Guangxi Graduate Education, Grant/Award Number: YCBZ2019051; National Natural Science Foundation of China, Grant/Award Numbers: 61761012, 61661011 Byline: Liwei Guo, Simin Li, Xing Jiang, Xin Liao, Ying Zhang, Bin Shi

3D printing is known as a fast, inexpensive, reproducible method for producing prototypes but is also fast becoming recognised as a scalable, advanced manufacture process. Two types of lab-scale, 3D printed plastic, fixed-film, flow-through photocatalytic reactors are described, both of which are sinusoidal in shape, and only differ in that one has no baffles, reactor A, whereas the other has, reactor B. Both reactors are lined with a P25 TiO 2 /polylactic acid (PLA) coating, which, after UVA pre-conditioning, is used to photocatalyse the bleaching of circulating aqueous solutions of either methylene blue, MB, or phenol, PhOH, repeatably, without any obvious loss of activity. The rate of the photocatalysed bleaching of MB exhibited by reactor B shows a much lower dependence upon flow rate than reactor A, due to the greater lateral mixing of the laminar flow streams produced by the baffles. The photonic efficiencies of reactor A for the photocatalysed bleaching of MB and PhOH were determined to be 0.025% and 0.052%, respectively, and the photocatalytic space-time yields (PSTY) to be 0.98 × 10 -4 and 1.49 × 10 -4 m 3 of reaction solution.m -3 reactor volume.day -1 .kW -1 , respectively. This is the first example of an all plastic, 3D printed photocatalytic reactor and demonstrates the advantages of 3D printing for prototyping. Given the 3D printing is a scalable process, possible potential areas of application are discussed briefly.
(© 2022. The Author(s).)

Openly shared low-cost electronic hardware applications, known as open electronics, have sparked a new open-source movement, with much untapped potential to advance scientific research. Initially designed to appeal to electronic hobbyists, open electronics have formed a global "maker" community and are increasingly used in science and industry. In this perspective article we review the current costs and benefits of open electronics for use in scientific research ranging from the experimental to the theoretical sciences. We discuss how user-made electronic applications can help (I) individual researchers, by increasing the customization, efficiency, and scalability of experiments, while improving data quantity and quality; (II) scientific institutions, by improving access to customizable high-end technologies, sustainability, visibility, and interdisciplinary collaboration potential; and (III) the scientific community, by improving transparency and reproducibility, helping decouple research capacity from funding, increasing innovation, and improving collaboration potential among researchers and the public. We further discuss how current barriers like poor awareness, knowledge access and time investments can be resolved by increased documentation and collaboration and provide guidelines for academics to enter this emerging field. We highlight that open electronics are a promising and powerful tool to help scientific research to become more innovative and reproducible and offers a key practical solution to improve democratic access to science.
(© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

Background: Following total sacrectomy, the continuity between the spine and pelvis is necessary for ambulation and to enable patients to resume daily living activities sooner during rehabilitation. Reconstructing spinopelvic stability after a total sacrectomy is a challenge that has not yet been overcome. Thus, the objectives of the present study are as follows:Establish a new system of reconstructing the spinopelvic region after a total sacrectomy using a rapid prototyping technique to design the sacral replacement pieces.Evaluate the biomechanical properties of this system.Study a new reconstruction system for the spinopelvic joint that reduces reconstruction failures after total sacrectomy, reducing postoperative complications and allowing early sitting and standing of these patients.
Methods: A sacral replacement implant was designed according to an authentic clinical case of a patient who had undergone a total sacrectomy. Using the finite element method, a biomechanical study was carried of 2 reconstructions that had been performed using the new prosthetic. The results of the study were compared with 4 other reconstruction models.
Results: A maximum von Mises stress of 112 MPa and a vertical displacement of -0.13 mm in L5 were observed in the models of the sacral implant that had been generated. A maximum rigidity of 861.5 Nm/mm was observed in the models when assuming a reduction in rigidity of more than 85% with respect to the other models assessed. In all models, maximum tension was concentrated in the rods joining L5 with the screws anchored to the pelvis.
Conclusions: The sacral prosthesis substitution after a total sacrectomy produced a profound reduction in stress in the instrumentation and the bone structure as well as smaller vertical displacement, the lowest values ever reported. These results indicated that the assembly was rigid and stable and would prevent the collapse of the spine in the pelvis. According to stress values, the replacement piece was not likely to rupture as a consequence of static load or implant fatigue.
(This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2022 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

We report automated fabrication of solid-contact sodium-selective (Na + -ISEs) and potassium-selective electrodes (K + -ISEs) using a 3D printed liquid handling robot controlled with Internet of Things (IoT) technology. The printing system is affordable and can be customized for the use with micropipettes for applications such as drop-casting, biological assays, sample preparation, rinsing, cell culture, and online analyte monitoring using multi-well plates. The robot is more compact (25 × 30 × 35 cm) and user-friendly than commercially available systems and does not require mechatronic experience. For fabrication of ion-selective electrodes, a carbon black intermediate layer and ion-selective membrane were successively drop-cast on the surface of stencil-printed carbon electrode using the dispensing robot. The 3D-printed robot increased ISE robustness while decreasing the modification time by eliminating manual steps. The Na + -ISEs and K + -ISEs were characterized for their potentiometric responses using a custom-made, low-cost (<$25) multi-channel smartphone-based potentiometer capable of signal processing and wireless data transmission. The electrodes showed Nernstian responses of 58.2 ± 2.6 mV decade -1 and 56.1 ± 0.7 mV decade -1 for Na + and K + , respectively with an LOD of 1.0 × 10 -5  M. We successfully applied the ISEs for multiplexed detection of Na + and K + in urine and artificial sweat samples at clinically relevant concentration ranges. The 3D-printed pipetting robot cost $100 and will pave the way for more accessible mass production of ISEs for those who cannot afford the expensive commercial robots.
(Copyright © 2022 Elsevier B.V. All rights reserved.)

Colorimetry methods, Humans, Microfluidics, Paper, Printing, Three-Dimensional, Reproducibility of Results, Drinking Water analysis, and Nitrites

To ensure safe drinking water, it is necessary to have a simple method by which the probable pollutants are detected at the point of distribution. Nitrite contamination in water near agricultural locations could be an environmental concern due to its deleterious effects on the human population. The development of a frugal paper-based microfluidic sensor could be desirable to achieve the societal objective of providing safe drinking water. This work describes the development of a facile and cost-effective microfluidic paper-based sensor for quantitative estimation of nitrite in aquatic environments. A simple punching machine was used for fabrication and rapid prototyping of paper-based sensors without the need of any specialized equipment or patterning techniques. A reusable 3D printed platform served as the support for simultaneous testing of multiple samples. The nitrite estimation was carried out with smartphone-assisted digital image acquisition and colorimetric analysis. Under optimized experimental conditions, the variation in average grayscale intensity with concentration of nitrite was linear in the range from 0.1 to 10 ppm. The limits of detection and quantitation were 0.12 ppm and 0.35 ppm respectively. The reproducibility, expressed as relative standard deviation was 1.31%. The selectivity of nitrite detection method was determined by performing interference studies with commonly existing co-ions in water, such as bicarbonates, chloride and sulphate. The paper-based sensor was successfully applied for estimation of nitrite in actual water samples and showed high recoveries in the range of 83.5-109%. The results were in good agreement with those obtained using spectrophotometry. The developed paper-based sensor method, by virtue of its simplicity, ease of fabrication and use, could be readily extended for detection of multiple analytes in resource-limited settings.
(Copyright © 2022 Elsevier Inc. All rights reserved.)

Additive Manufacturing (AM) comprises a variety of techniques that enable fabrication of customised objects with specific attributes. The versatility of AM procedures and constant technological improvements allow for their application in the development of medicinal products and medical devices. This review provides an overview of AM applications related to respiratory sciences. For this purpose, both fields of research are briefly introduced and the potential benefits of integrating AM to respiratory sciences at different levels of pharmaceutical development are highlighted. Tailored manufacturing of microstructures as a particle design approach in respiratory drug delivery will be discussed. At the dosage form level, we exemplify AM as an important link in the iterative loop of data driven inhaler design, rapid prototyping and in vitro testing. This review also presents the application of bioprinting in the respiratory field for design of biorelevant in vitro cellular models, followed by an overview of AM-related processes in preventive and therapeutic care. Finally, this review discusses future prospects of AM as a component in a digital health environment.
(Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Engineering regulatory parts for improved performance in genetic programs has played a pivotal role in the development of the synthetic biology cell programming toolbox. Here, we report the development of a novel high-throughput platform for regulatory part prototyping and analysis that leverages the advantages of engineered DNA libraries, cell-free protein synthesis (CFPS), high-throughput emulsion droplet microfluidics, standard flow sorting adapted to screen droplet reactions, and next-generation sequencing (NGS). With this integrated platform, we screened the activity of millions of genetic parts within hours, followed by NGS retrieval of the improved designs. This in vitro platform is particularly valuable for engineering regulatory parts of nonmodel organisms, where in vivo high-throughput screening methods are not readily available. The platform can be extended to multipart screening of complete genetic programs to optimize yield and stability.

Background and Objective: COVID-19 severity spans an entire clinical spectrum from asymptomatic to fatal. Most patients who require in-hospital care are admitted to non-intensive wards, but their clinical conditions can deteriorate suddenly and some eventually die. Clinical data from patients' case series have identified pre-hospital and in-hospital risk factors for adverse COVID-19 outcomes. However, most prior studies used static variables or dynamic changes of a few selected variables of interest. In this study, we aimed at integrating the analysis of time-varying multidimensional clinical-laboratory data to describe the pathways leading to COVID-19 outcomes among patients initially hospitalised in a non-intensive care setting.
Methods: We collected the longitudinal retrospective data of 394 patients admitted to non-intensive care units at the University Hospital of Padova (Padova, Italy) due to COVID-19. We trained a dynamic Bayesian network (DBN) to encode the conditional probability relationships over time between death and all available demographics, pre-existing conditions, and clinical laboratory variables. We applied resampling, dynamic time warping, and prototyping to describe the typical trajectories of patients who died vs. those who survived.
Results: The DBN revealed that the trajectory linking demographics and pre-existing clinical conditions to death passed directly through kidney dysfunction or, more indirectly, through cardiac damage. As expected, admittance to the intensive care unit was linked to markers of respiratory function. Notably, death was linked to elevation in procalcitonin and D-dimer levels. Death was associated with persistently high levels of procalcitonin from admission and throughout the hospital stay, likely reflecting bacterial superinfection. A sudden raise in D-dimer levels 3-6 days after admission was also associated with subsequent death, possibly reflecting a worsening thrombotic microangiopathy.
Conclusions: This innovative application of DBNs and prototyping to integrated data analysis enables visualising the patient's trajectories to COVID-19 outcomes and may instruct timely and appropriate clinical decisions.
(Copyright © 2022 Elsevier B.V. All rights reserved.)

Purpose: An automated algorithm for generating realizable MR gradient and shim coil layouts based on the boundary element method is presented here. The overall goal is to reduce postprocessing effort and thus enable for rapid prototyping of new coil designs. For a given surface mesh and target field, the algorithm generates a connected, non-overlapping wire path.
Methods: The proposed algorithm consists of several steps: Stream function optimization, two-dimensional surface projection, potential discretization, topological contour sorting, opening and interconnecting contours, and finally adding non-overlapping return paths. Several technical parameters such as current strength, inductance and field accuracy are assessed for quality control.
Results: The proposed method is successfully demonstrated in four different examples. All exemplary results demonstrate high accuracy with regard to reaching the respective target field. The optimal discretization for a given stream function is found by generating multiple layouts while varying the input parameter values.
Conclusion: The presented algorithm allows for a rapid generation of interconnected coil layouts with high flexibility and low discretization error. This enables to reduce the overall post-processing effort. The source code of this work is publicly available ( https://github.com/Philipp-MR/CoilGen).
(© 2022 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

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 .
(© 2022. The Author(s).)

Purpose: This study compared the dimensional changes between computer-aided design and computer-aided manufacturing (CAD-CAM) milled complete denture bases (CDBs) and three-dimensional (3D) printed CDBs.
Materials and Methods: One maxillary completely edentulous stone model was fabricated with three reference points at the incisive papilla, right molar, and left molar areas marked as X, Y, and Z, respectively. It was scanned to produce a standard tessellation language (STL) file, which was imported to a metal milling machine software to produce the metal model. This metal model was used to fabricate 30 CDBs for analysis. The CDBs were divided into three groups (n = 10 each) according to the fabrication method used as follows: Group 1, CAD-CAM milled CDBs; Group 2, 3D printed CDBs; and Group 3, conventional compression molded CDBs. The CDBs of all groups were scanned after fabrication, and the dimensional changes in each were evaluated by two methods. The first was the two-dimensional evaluation method that involved linear measurement of the distances between the reference points (X-Y, X-Z, and Y-Z) of the scanned reference cast and dentures. The second method was the 3D evaluation method that involved the superimposition of the STL files of the dentures on the STL file of the reference cast. Data were calculated and were statistically analyzed using one-way analysis of variance and Tukey's pairwise post hoc tests.
Results: There was a significant difference in the dimensional accuracy between the CAD-CAM milled, 3D printed, and conventional compression molded CDBs (p < 0.05).
Conclusion: The dimensional accuracy of the CAD-CAM milling system in complete denture fabrication is superior to that of the compression molding and 3D printing systems.
(© 2022 by the American College of Prosthodontists.)

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.

Background: The rise of digital methods and computational tools has opened up the possibility of collecting and analyzing data from novel sources, such as discussions on social media. At the same time, these methods and tools introduce a dependence on technology, often resulting in a need for technical skills and expertise. Researchers from various disciplines engage in empirical bioethics research, and software development and similar skills are not usually part of their background. Therefore, researchers often depend on technical experts to develop and apply digital methods, which can create a bottleneck and hinder the broad use of digital methods in empirical bioethics research.
Objective: This study aimed to develop a research platform that would offer researchers the means to better leverage implemented digital methods, and that would simplify the process of developing new methods.
Methods: This study used a mixed methods approach to design and develop a research platform prototype. I combined established methods from user-centered design, rapid prototyping, and agile software development to iteratively develop the platform prototype. In collaboration with two other researchers, I tested and extended the platform prototype in situ by carrying out a study using the prototype.
Results: The resulting research platform prototype provides three digital methods, which are composed of functional components. This modular concept allows researchers to use existing methods for their own experiments and combine implemented components into new methods.
Conclusions: The platform prototype illustrates the potential of the modular concept and empowers researchers without advanced technical skills to carry out experiments using digital methods and develop new methods. However, more work is needed to bring the prototype to a production-ready state.
(©Manuel Schneider. Originally published in JMIR Formative Research (https://formative.jmir.org), 05.05.2022.)

Elastomers, Feedback, Magnetic Phenomena, Mechanical Phenomena, and Robotic Surgical Procedures

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.

Electrodes, Glucose, Gold chemistry, Hydrogen Peroxide, Silver, Electrochemical Techniques, and Microfluidics

We present a low-cost, accessible, and rapid fabrication process for electrochemical microfluidic sensors. This work leverages the accessibility of consumer-grade electronic craft cutters as the primary tool for patterning of sensor electrodes and microfluidic circuits, while commodity materials such as gold leaf, silver ink pen, double-sided tape, plastic transparency films, and fabric adhesives are used as its base structural materials. The device consists of three layers, the silver reference electrode layer at the top, the PET fluidic circuits in the middle and the gold sensing electrodes at the bottom. Separation of the silver reference electrode from the gold sensing electrodes reduces the possibility of cross-contamination during surface modification. A novel approach in mesoscale patterning of gold leaf electrodes can produce generic designs with dimensions as small as 250 μm. Silver electrodes with dimensions as small as 385 μm were drawn using a plotter and a silver ink pen, and fluid microchannels as small as 300 μm were fabricated using a sandwich of iron-on adhesives and PET. Device layers are then fused together using an office laminator. The integrated microfluidic electrochemical platform has electrode kinetics/performance of Δ Ep = 91.3 mV, Ipa / Ipc = 0.905, characterized by cyclic voltammetry using a standard ferrocyanide redox probe, and this was compared against a commercial screen-printed gold electrode (Δ Ep = 68.9 mV, Ipa / Ipc = 0.984). To validate the performance of the integrated microfluidic electrochemical platform, a catalytic hydrogen peroxide sensor and enzyme-coupled glucose biosensors were developed as demonstrators. Hydrogen peroxide quantitation achieves a limit of detection of 0.713 mM and sensitivity of 78.37 μA mM -1 cm -2 , while glucose has a limit of detection of 0.111 mM and sensitivity of 12.68 μA mM -1 cm -2 . This rapid process allows an iterative design-build-test cycle in under 2 hours. The upfront cost to set up the system is less than USD 520, with each device costing less than USD 0.12, making this manufacturing process suitable for low-resource laboratories or classroom settings.

Problem: Physicians are playing a growing role as clinician-innovators. Academic physicians are well-positioned to contribute to the medical device innovation process, and yet few medical school curricula provide students opportunities to learn the conceptual framework for clinical needs finding, needs screening, concept generation and iterative prototyping, and intellectual property management. This framework supports innovation and encourages the development valuable interdisciplinary communication skills and collaborative learning strategies.
Approach: Our university offers a novel 3-year-long medical student Longitudinal Interdisciplinary Elective in Biodesign (MSLIEB) that teaches medical device innovation in 4 stages: (1) seminars and small group work, (2) shared clinical experiences for needs finding, (3) concept generation and product development by serving as consultants for biomedical engineering capstone projects, and (4) reflection and mentorship. The MSLIEB objectives are to: create a longitudinal interdisciplinary peer mentorship relationship between undergraduate biomedical engineering students and medical students; and encourage codevelopment of professional identities in relation to medical device innovation.
Outcomes: The MSLIEB enrolled 5 entering cohorts from 2017-2021 with a total of 37 medical student participants. The first full entering cohort of 12 medical students produced 8 mentored biomedical engineering capstone projects, 7 of which were based on clinical needs statements derived from earlier in the elective. Medical student participants have coauthored poster and oral presentations, contributed to projects that won WolfieTank, a university-wide competition modeled after the television show Shark Tank, and participated in the filing of provisional patents. Students reflecting on the course reported a change in their attitude towards existing medical problems, felt better-equipped to collaboratively design solutions for clinical needs, and considered a potential career path in device design.
Next Steps: The MSLIEB will be scaled-up by recruiting additional faculty, broadening clinical opportunities to include the outpatient setting, and increasing medical student access to rapid prototyping equipment.