Fundamentals of Piezoelectricity and Piezoelectric Materials for Ultrasonic Motors

Abstract

The development of ultrasonic motors is a highlight in the application of piezoelectric materials. Ultrasonic motors take advantage of converse piezoelectricity of piezoelectric materials to yield mechanical output from converting electrical energy. It is no doubt that piezoelectric materials are in the central position that controls the performance of the devices. In this chapter, we will review piezoelectric materials and their properties from the aspect of their applications in ultrasonic motors. The chapter begins with a brief overview of historical development of piezoelectric materials, and then a detailed explanation of the electrical and mechanical properties of piezoelectric materials will be discussed in the second and the third sections, where the piezoelectric constitutive equations are specially stressed. Piezoelectric vibrators, as basic units of piezoelectric devices, and their vibration types will be described in sequence. In the last two sections, the application of piezoelectric materials in ultrasonic motors and some advances in novel materials will be introduced.