国際会議
Keynote Speech at Acoustofluidics 2025 in Dresden, Germany
BEGINNING OF ACTUATOR APPLICATIONS OF SURFACE ACOUSTIC WAVE DEVICES
Abstract
High power density and high vibration velocity are key issues for piezoelectric transducers in actuator applications. Surface acoustic wave devices use crystal piezoelectric materials, which provides excellent performance in generating high intensity acoustic waves. About 30 years ago, we tried to introduce SAW transducers into vibration actuators for friction drive motors, atomizers, and gyro-sensors. However, the problem was that at frequencies higher than 10 MHz, only small vibration amplitudes of less than 10 nanometers could be obtained. For friction drive motors such as ultrasonic motors, the smaller the vibration amplitude the more important the contact condition become. To solve the contact problem, high contact pressure conditions were considered at the slider contact area. With the specially designed slider, the SAW motor operated normally. Intermittent power supply was applied to the SAW atomizer in order to operate at a high vibration velocity with moderate average input power. The high frequency operation of tens MHz produced a much smaller particle mists than typical ultrasonic atomizers operating at several tens of kHz. At same time, we tried newly designed SAW gyro sensor, we could not get signals. Later, however, several groups succeeded in obtaining signals.
Bio
Minoru Kurosawa (formerly Kuribayashi) received the B.Eng. degree in electrical and electronic engineering, and the M. Eng. and D. Eng. degrees from Tokyo Institute of Technology, in 1982, 1984, and 1990, respectively. He started the research on ultrasonic motors using bulk PZT in 1983. He became a research associate of the Precision and Intelligence Laboratory, Tokyo Institute of Technology in 1984. In 1992, he became an associate professor at the Department of Precision Machinery Engineering, The University of Tokyo, where he started research on SAW motors and atomizers, piezo film deposition and actuators, and 1bit signal processing. In 1999, he returned to Tokyo Institute of Technology. He has been working on SAW motors, ultrasonic motors, piezo films, 1bit digital signal processing and its application. Currently, he is interested in audio engineering, and his research on distortion of passive components such as resisters, capacitors, coils, and cables for high-fidelity audio systems.
ドレスデンで開催された国際会議（Acoustofluidics 2025: 2025年8月20-22日）に招待され，弾性表面波霧化デバイスに関する基調講演を行いました。この講演は，我々が1994年に東京大学にて動作を実証した弾性表面波霧化デバイスの論文が出版されて30年という節目の年であることと，会議を主催したドレスデン工科大学が，弾性表面波霧化デバイスを医療用に実用化したことを記念して行われました。