Microsystem Technologies; June 2005, Vol. 11 Issue: 6 p429-437, 9p
Abstract This study presents a new method of fabricating and integrating micro cylindrical lenses (MCLs) into an in-plane micro optical system. The characterizations of MCLs, which are made of SU-8 negative photoresist, are also reported in this study. Many demands, especially for arbitrary lens shapes and accurate alignment, can be met by the proposed method. The measurements of size revealed that SU-8 MCLs swelled, but the amount of swelling maintained constant for at least six months. Two factors were demonstrated to govern the swelling of SU-8 structures, and can be compensated for in the design of the mask. The SU-8 MCLs are shown to exhibit function with a satisfactory optical property. Fluorescence is collimated and focused in a micro channel, demonstrating the potential of MCLs to detect laser-induced-fluorescence (LIF). The fluorescence behavior of SU-8 is also examined herein. The advantages of rapid prototyping and easy integration of SU-8 MCLs have a range of many applications, especially in in-plane micro optical configurations.
Utsumi, Y., Ozaki, M., Terabe, S., and Hattori, T.
Microsystem Technologies; April 2005, Vol. 11 Issue: 4-5 p235-239, 5p
Abstract We fabricated the electrophoresis microchips using the UV polymerization technique. We employed plastic substrates that were suitable for rapid prototyping instead of glass and quartz. A thick UV negative photo resist was used to form molds and poly-dimethylsilozane (PDMS) was polymerized by a thermal curing process on the mold to obtain replica microchips. Electroosmotic flow (EOF) was measured to evaluate the surface. Characteristic differences between UV-fabricated and SR-fabricated microchips were evaluated by electro osmotic flow (EOF) measurement. It was observed that microchannels fabricated by SR lithography show constant peak heights and FWHMs. We also investigated the effect of the change of the channel width along the EOF direction. It is demonstrated that broadening width channel significantly restricts the sample diffusion towards the EOF direction and leads to the high resolusion separation on the PDMS microchips. Thus the advantage of the application of SR lithography to the mold fabrication is also demonstrated.
In this paper, we report on first stage results on our work on the design and prototyping of a simple polycarbonate micro-mixer. CFD simulations indicate that the elliptical shape of the mixer appears to eliminate dead volumes and to result in more uniform flow and hence more uniform mixing. The mixer has also been characterised spectrophotometrically in a simple way. A simple design may be advantageous in that it may be more reliable in the micro-scale. It is certainly easier to manufacture.
Abstract A modular and parametric approach to FE-modelling is presented which allows rapid virtual prototyping for MEMS and other microelectronics packages with respect to some topical reliability issues: Thermal management and thermo-mechanical fatigue. Thereby the method of automatic model generation by modular parametric modelling is outlined and some examples featuring the required solution techniques are given. This simulation procedure forms part of a comprehensive design optimisation process in the field of predictive engineering.
Abstract Ceramic microreactors can be used for applications that cannot be covered by metal or polymer systems, because special material properties, such as high thermal and chemical resistance are required. However, application of ceramic microcomponents often fails due to the time-consuming and costly manufacturing of components with patterning details in the micrometer range. A promising solution to this problem is a rapid prototyping process chain. It offers a fast and precise fabrication of ceramic components down to the micrometer range by combining stereolithography and low-pressure ceramic injection molding. Its fast and flexible tooling allows rapid product development and manufacturing of ceramic components as functional models or in small series. For use in chemical microreaction technology, a modular ceramic microreactor with inner dimensions in the sub-millimeter range has now been developed by means of this process chain.
Abstract The cost-effective fabrication process for high-aspect-ratio microstructures using X-rays depends largely on the availability and quality of X-ray masks. The fabrication of X-ray masks using commercially available graphite sheet stock, as a mask membrane is one approach that is designed to reduce cost and turnaround time. Rigid graphite offers unique properties, such as moderate X-ray transmission, fairly low cost, electrical conductivity, and the ability to be used with either subtractive or additive processes [1, 2].
This paper will demonstrate the potential of a cost-effective, rapid prototyping of high-aspect-ratio microstructures (HARMs) using graphite masks. The graphite wafer accommodates both the intermediate mask and the working mask. In order to allow a direct comparison of the graphite mask quality with other X-ray masks, the primary pattern was derived from a Ti X-ray mask using soft X-ray lithography (XRL).
Abstract An innovative method for fabrication and rapid prototyping of high-aspect ratio micromechanical components in photoresist is discussed. The photoresist is an epoxy-negative-tone resist, called SU-8, which can be structured to more than 2 mm in thickness by UV exposure. Small gears of 530 μm in diameter and 200 μm in thickness have been realized in this photoplastic and their functionality has been demonstrated. In addition a process called MIMOTECTM (MIcroMOlds TEChnology) has been established for the fabrication of metallic micromolds. MIMOTECTM is based on the use of the SU-8 spun on high thicknesses and electrodeposition of nickel. Thermoplastic microcomponents have been injected and mounted in watches.
Abstract The X-ray micromachining activities at CAMD are described. Through the HI-MEMS Alliance Program, CAMD has developed an extensive technical infrastructure and process experience. The “X-ray Print-Shop” supports prototyping and is prepared for cost effective low-to-medium volume production of primary parts with high aspect ratio, including exposure of multiple level devices with alignment, as well as tilted and rotated exposures. Important lessons learnt during the course of the program will be reported. An up-grade of the facility to install a 7.5 Tesla superconducting wiggler in the ring is in progress. It will produce hard X-rays for ultra-deep X-ray lithography.