旭硝子財団助成研究成果報告2018

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50吉田　慎哉57ShinyaYOSHIDA人間共生ロボットのための超高性能圧電単結晶 MEMS 超音波距離画像センサーの創製(2016採択)Development of ultrahigh performance piezoelectric monocrystalline MEMS ultrasonic range finder for human-friendly robot(Project 2016)旭硝子財団　助成研究成果報告（2018）we have focused on multi-layered Dirac materials for exploring their potential thermoelectric applica-tions. In particular, we aim to reveal the overall features of Seebeck and Nernst effects for EuMnBi2, where the Dirac fermion transport can be controlled by magnetic order of the block layer. As a result, we have observed the excellent thermoelectric power factor and large Nernst signals comparable to the Seebeck signals, originating from the extremely high mobility of Dirac fermions. Furthermore, we have found that the Seebeck and Nernst effects for this compound are strongly coupled with the Eu local moments, which may lead to novel correlated thermoelectric phenomena.本研究の目的は，圧電薄膜を用いながら，低駆動電圧で数mの測距が可能な小型の超音波距離画像センサーを創り出し，ロボットシステムへの応用可能性を示すことである．本研究では，次のような要素技術開発および実証実験を行った．1. 高い信頼性を持つ超高性能PZT系単結晶薄膜のSi基板上への形成2. 最適なエピタキシャルバッファ層の探索3. pMUTレンジファインダーの試作と高性能測距能の実証その結果，1Vp-pという極めて小さな駆動電圧でも，2m以上の測距を達成できるデバイスの試作に成功した．これにより，小型で安価なロボット用ソナーシステムを実現できる可能性が示唆された．また，体表に分布させる形の超小型近接覚センサモデュールの実現可能性も実証した．The purpose of this study is to create a compact-size ultrasonic range-finding imager with a capability of long range finding such as several meters for applications to a robot system although the device utilizes a piezoelectric thin film and is driven by low driving voltage. We developed essential technologies and per-formed demonstration experiments as follows. 1. Fabrication of a reliable and ultrahigh-performance PZT-based monocrystalline thin film on Si.2. Investigation of an optimal epitaxial buffer layer structure. 3. Prototyping of a pMUT rangefinder based on this PZT film and demonstration of its high-perform-ance range-finding ability.As a result, we successfully developed a range-finding device with the length of > 2 m at a small voltage of 1 Vp-p. That verified this pMUT rangefinder has the potency to realize a small and cheap sonar system for safety operation of a robot. The realization possibility of a proximity sensor module on the body surface of a robot was also demonstrated.