Piezoelectric ceramic ultrasonic motors

Piezoelectric ceramic ultrasonic motors are a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. Compared to conventional electromagnetic and electrostatic motors, they have features such as high torque at low speed, absence of electromagnetic disturbance, no noise,high holding torque, quick response, and simple construction, etc. They have been applied in the fields of precision instruments, aeronautics and aerospace, control automation, office automation, micromechanical systems, microfabrication, precision positioning, etc. This paper summarizes their features,recent advances in related research and several suggestions on futher development.