This paper reports on a newly developed coarse-grained molecular dynamics simulation for epoxy-based chemically-amplified photoresist dedicated to MEMS. To analyze photoresists material properties, Kremer-Grest model (bead-spring model) with an extended angle bending potential was newly employed. A uniaxial elongation simulation and the molecular diffusion simulation were performed to analyze the dependence of an elastic modulus and a molecular permeability on the cross-linked ratio of a photoresists, since these characteristics are important for a permeable membrane made of photoresist to control biological molecules diffusion in biomedical applications. The simulated dependencies of the elastic modulus and the molecular permeability on the cross-linked ratio of photoresists showed good correspondences with the experimental results. This suggests a photoresists membrane can be used as a molecular permeable membrane with controllable permeability by varying photolithography process parameters.

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Light-driven actuators result in the miniaturization of micro-devices because such actuators can be driven by a non-contact energy supply. PLZT is a ferroelectric material that exhibits a photostrictive effect. We have succeeded in driving a photoresponse actuator by using the PLZT film. The PLZT film was deposited on a titanium substrate by using the hydrothermal method. The PLZT film was evaluated by x-ray diffraction and piezoelectricity. The actuator has a simple structure in which an indium tin oxide (ITO) transparent electrode is deposited on the surface of the PLZT film. The actuator is driven by the ultraviolet (UV) light. To confirm the driven phenomenon, the photoresponse drive was evaluated by measuring the displacement, electric current and surface temperature. As an example of a light-driven application using the PLZT film actuator, we also fabricated and evaluated a light-driven valve. We have succeeded in changing the flow rate when the intensity of the UV light increased.

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Electric double layer capacitor (EDLC) is attractive electrical energy storage for micro-machines because it has long-lifetime and high-responsiveness. One of the requirements is how to increase energy density, especially on micro-chip in which it is difficult to use high-volume electrodes of capacitor. We propose an approach to use carbon onion as materials of polarized electrodes. Carbon onion is an allotrope of nano-carbon materials and it is easily produced from carbon-black or nano-diamond particle. In this paper six carbon onions prepared under different conditions and a conventional activated carbon powder are prepared and their electrical properties are compared by cyclic voltammetry. Specific capacitance of carbon onion reaches 25.7 F/g and it is much higher than that of activated carbon 6.8 F/g, while activated carbon has three times higher specific surface than carbon onion. The results indicate that carbon onion is effective to improve an energy density and one of strong candidates of electrode materials for micro-machines fabricated on a chip.

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Combinatorial search is one of the useful methods that could search for optimal composition of alloy materials or novel alloy materials. Combinatorial sputtering provides sample group (library) having different compositions in a limited place. Then, the properties of the samples can be scanned in an efficient way. In this research, it was studied that magnetostrictive material with high magnetostriction, relative permeability and resistivity. Desired value of magnetostriction is more than 20×10^-6, relative permeability is more than 4000, and resistivity is more than 100 µΩ·cm. As a result, composition that Cr content is less than 14 at.% fill the desired value of relative permeability, and more than 10 at.% fill the desired value of resistivity. There is possibility to fill the desired value of magnetostriction.

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Thin film shape memory alloys (SMAs) are promising materials for micro-machines because of their high-output power, large strain, and actuation without high voltage. To search for compositions of suitable thin film SMAs for each application, combinatorial technique is useful tool, however the technique requires high-throughput characterization method for thermal property which is an important property of thin film SMAs such as two way martensitic transformation temperature and thermal hysteresis. In this paper, novel high-throughput characterization method for such properties using thermography is proposed and demonstrated. Compositionally integrated thin film SMA samples (TiNiPd) with only 1mm² of each area are characterized at once. The difference of martensitic and reverse martensitic transformation temperature against those temperatures measured by a conventional method, differential scanning calorimetry, is about 5K.

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A non-contact voltage sensor that realizes isolation from the main circuit of the power line is proposed. A high voltage generates an electrostatic force, and sensing is based on the nature of the electrostatic force. Applying the electrostatic force can be like adding a negative spring to a resonator in that the resonance frequency decreases with the voltage. A parallel plate electrode is used for sensing due to the strong gap dependency, and a comb electrode is used to excite the vibration of the resonator because it contributes very little to the gap dependence. The relationship between the shift of the resonance frequency and the applied voltage is well-explained by theory.

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Chip to wafer (C2W) bonding is attractive because of the flexibility for various device integration and no limitations on both wafer and chip size, which is important for MEMS ubiquitous applications as well as to reduce the production cost. We have proposed a 2-step approach for MEMS-IC size free integration by using carrier wafer. Based on our previous results, this work developed a prototype high-efficiency C2W self-alignment and temporary bonding system, which includes vacuum-chuck, micro-dispenser and X-Y hot plate stage. This paper investigated the effects of process parameters, e.g. volume of H₂O, wafer temperature during self-alignment, annealing process, on alignment accuracy and temporary bonding etc. Those results presented above clearly demonstrated that the proposed approach is promising for MEMS ubiquitous applications and other consumer electric production.

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