A cylindrical micro ultrasonic motor using a micro-machined bulk piezoelectric transducer

A micro ultrasonic motor using a micro-machined bulk piezoelectric transducer is introduced. A cylindrically shaped bulk piezoelectric transducer, with diameter 0.8 mm and height 2.2 mm, was developed as the stator transducer for a traveling wave type ultrasonic motor. We have fabricated a cylindrical micro ultrasonic motor, with diameter of 2.0 mm and height of 5.9 mm, using the stator transducer. We have also evaluated some characteristics and succeeded in driving the micro ultrasonic motor.