Linear ultrasonic piezoelectric actuator

A prototype of a linear ultrasonic piezoelectric actuator (LUPA) was developed, and the fundamental characteristics were measured. The results imply that the LUPA has the advantages of compactness, standstill force without excitation, and a large torque in the low-speed range. The disadvantages are that the mechanism of force generation is friction, which may not be steady, and a 30-50 kHz power supply is required.<<ETX>>