This text investigates the fundamental principles, operational mechanics, and practical applications of ultrasonic motors, a technology driven by the piezoelectric effect. Written by the motor's inventor, Toshiiku Sashida, alongside electrical engineering expert Takashi Kenjo, the book provides a comprehensive theoretical framework for understanding how these devices achieve high torque and power-to-weight ratios at low speeds. The authors synthesize physical theory with engineering design to explain the transition from conventional electromagnetic motors to ultrasonic alternatives.

Experts and researchers identify this monograph as a foundational text for understanding the early development and technical specifications of ultrasonic motor technology. Readers frequently note the academic density of the prose, which serves as a primary reference for engineers and students entering the field of precision motion control.