Characteristic measurement of a surface acoustic wave nano-stepping motor by using a fiber-optic Michelson interferometer

Abstract

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