A comprehensive tutorial on ultrasonic motors for practicing engineers researchers and graduate students ultrasonic motors technologies and applications describes the operating mechanism electromechanical coupling models optimization design of structural parameters testing methods and drive control techniques of various ultrasonic motors and their applications. A comprehensive tutorial on ultrasonic motors for practicing engineers researchers and graduate students ultrasonic motors technologies and applications describes the operating mechanism electromechanical coupling models optimization design of structural parameters testing methods and drive control techniques of various ultrasonic motors and their applicationsdr chunsheng zhao is a . These motors have very high efficiency and their efficiency is insensitive to their size demerits of ultrasonic motors a high frequency power supply is required as these motors operate on friction durability is very less these motors have drooping speed torque characteristics applications of ultrasonic motors used for the autofocus of camera lens