シリコンスライダを用いた弾性表面波モータ  [in Japanese] Surface Acoustic Wave Motor with a Silicon Slider  [in Japanese]

駆動表面を微細加工したシリコンスライダを用いることにより、微小鋼球による多接点スライダを用いた場合に比べ、約8倍の推力と約4倍の最大速度を得ることに成功した。スライダとステータ振動子との接触面積を大きくするために、シリコンスライダを作成した。その結果、最大推力3.5N、最大速度1m/s以上、分解能40nm以下、応答周波数130kHz以上という駆動特性が得られた。シリコンスライダの形状を変えることにより、更なる駆動特性の向上の可能性も示された。また、駆動エネルギを還流する方法を考案し、実験により実証した。

This paper describes an application of surface acoustic wave(SAW)device to an ultrasonic linea motor.A merit of SAW device is high energy density and small size.But driving frequency is around 10 MHz or higher.In spite of the difficulty of high frequency, the high energy density is attractive for actuators.The SAW linear motor's no-load speed and maximum output force were 1.1m/sec and 3.5 N using a silicon slider.The silicon slider dimensions were 4x4x0.3 mm^3.We made a lot of 30 micron diameter projections on the silicon surface.The acceleration was 1000m/sec^2 and response frequency was 130 kHz or more.The 40 nm step motion was achieved.The SAW motor is expected to be high speed, quick response, and high resolution micro actuator.The most significant problem was the high voltage of the driving.For the previous experiments, we required more than 100 V, due to the primitive design of the driving electorode.Our new designed electrode proved that the driving voltage was reduced less than 10 V to excite the traveling wave.