Ultrasonic Linear Motors Using Piezoelectric Actuators

A new type of linear motor using a piezoelectric actuator has been developed in which a mechanically resonating part slides on a stationary rail. The slider consists of two bimorphs, or a multilayered piezoelectric actuator with a bonded elastic vibratory fork. The key to obtaining a smooth movement is to realize a slight deviation in the resonance frequency of each leg of the fork so that the moving direction can be controlled by changing the drive frequency.