表面聲波微步進馬達的特性量測

Abstract

本研究主要探討表面聲波元件應用於奈米尺度的步進致動原理及技術。利用半導體製程技術在Y+128度切面之鈮酸鋰基材上製作交指叉換能器，產生10 MHz高頻的X-波傳表面聲波，藉助定子與滑座間的正向接觸力與摩擦力，推動滑座作線性步進移動。採用光纖式麥克森干涉儀量測滑座的步進位移，初步評估表面聲波馬達之性能。本研究內容包括表面聲波元件的設計原理、交指叉換能器的實驗分析、光纖式麥克森干涉儀及表面聲波馬達之量測結果。光纖式麥克森干涉儀的訊號經數位濾波處理及位移解調後，解析度可達本實驗所需，此表面聲波馬達可達奈米等級的步進位移。

The actuation technique of a surface acoustic wave (SAW) stepper with nanometer scale linear motion is experimentally investigated in this thesis. The SAW motor is composed of a stator made of a Y+128o cut, X-propagation lithium niobate substrate and silicon sliders with an array of pillar projections manufactured by semiconductor fabrication technique. Two sets of interdigital transducers deposited on the substrate are used to generate Rayleigh waves with driving frequency up to 9.7 MHz. The SAW motor is driven by friction exerted on the contact area between the slider and surface acoustic waves in retrogressive elliptical locus. Stepping motion of the SAW motor is measured directly by a fiber-optic Michelson interferometer with demodulation in digital signal processing method. A several nanometer displacement in each step is achieved during the experiment.