もはや現実のものになりつつあるIoT社会の到来により，あらゆる「モノ」のデータを取得するセンサに対する要求は，高機能・多様化し続けています。そのために用いられる材料も，従来センサ・マイクロマシンにおいて標準的に利用されてきたものに加え，医療，ヘルスケア，環境，車

Tactile devices that provide touch sensation to humans by direct contact have been realized. A tactile device based on a piezoelectric MEMS is improved in this study. The driving voltage is lowered by using multilayer lead zirconate titanate (PZT) thin film. The lower voltage is experimentally validated by measuring the cantilever displacement in the device. The displacement per voltage becomes four times larger by using four layers of PZT thin film. In addition, the polymer supporting material is also investigated to reduce the temperature dependence of the device. By using polyimide as an alternative to conventional SU-8, not only the initial warpage but also the temperature dependence is dramatically improved. The driving test of the polyimide device reveals cantilever displacement comparable to that in conventional devices. In conclusion, structural improvements resulted in low-voltage actuation and reduced warpage of the piezoelectric MEMS tactile device.

Humans recognize surface texture of objects by perception of force and vibration during contact. In our previous work, it is demonstrated that multi-axial contact force can be detected by tactile sensor using Si microcantilevers with thin film strain gauge embedded in the elastomer. In this work, to detect vibration, Si microcantilever with PZT thin film embedded in the elastomer has been newly fabricated and characterized. As a result, the output voltage depending on vibration frequency can be successfully obtained from PZT on the fabricated microcantilever. Furthermore, the microcantilever has been thinned by dry etching process after fabrication and it is suggested that sensitivity and frequency characteristics of the vibrational tactile sensor can be controlled.

Recently, soft robots have attracted interest of researchers. The advantages of the soft robots are the flexibility and simplicity of the structure. However, in order to implement complex motions with the robots, sensors and wires are required to measure the condition of the robots. In this study, we propose a method to actuate soft robots with pressurized liquid metal. The method enables the robots to provide both electrical signal and force. We prototyped a McKibben artificial muscle actuator and evaluated the mechanical properties and electrical properties to verify the proposed concept.

This letter describes a resonant-type magnetic sensor with piezo-electric film elements on an Si micro-bridge resonator and other micro-bridge structures with magneto-strictive film to provide structural deformation by external magnetic flux. The sensor was successfully fabricated with thick sol-gel PZT film (1.1 µm) and Fe₆₅Pd₃₅ magneto-strictive film (2 µm) on Si (5 µm) micro-bridges. The resonant behavior was evaluated using the output voltage from the PZT film element on the bridge resonator. The resonant frequency decreased with increasing applied magnetic flux because initial strain of the micro-bridge with the tensile stress of PZT film was relaxed by the magneto-striction.

Filters for drink extraction are made of natural, plastic fibers or combinations of the fibers. However, we often feel unfavorable flavors of extraction solutions caused by terpenes included in raw materials and residual chemical substances in production processes and so on. Our final goal is to develop a filter for drink extraction without unfavorable flavors felt by human. In this study, we demonstrate that a fabricated polyethylene terephthalate (PET) non-woven fabric not containing plant-derived fibers and chemical reagents such as adhesives and dispersant is suitable as a filter for drink extraction using a taste sensor and GC-MS as objective evaluations and a sensory evaluation and GC-olfactometry as subjective evaluation. The taste sensor detected bitterness as well as sensory evaluation, which indicated that it was a good evaluation method in the evaluation of the taste of the beverage filter. In addition, it found that the heat-sealing paper had a more bitter taste than the PET non-woven fabric. In GC-MS and odor sniffing GC, PET non-woven fabric does not contain non-2-enal, which is a factor of cardboard flavor, and can be a useful beverage filter. Thus, the results obtained in this paper suggest that the fabricated PET non-woven fabric will be a great material, which does not impart a different flavor to the beverage.