Piezoelectric micromotors for microrobots

Small (a few millimeters in diameter) piezoelectric motors using ferroelectric thin films were fabricated. The films are designed to create a traveling wave in a stator structure. A small glass lens placed upon it becomes the spinning rotor. Piezoelectric ultrasonic motors overcome such problems associated with electrostatic micromotors as low torque, friction, and the need for high-voltage excitation. More importantly, they used offer a much simpler mechanism for coupling mechanical power out. Using thin films of lead zirconate titanate (PZT) on silicon nitride membranes, various types of actuator structures can be fabricated. Motors can be manufactured in a batch printing process instead of being individually machined. Combining new robot control systems with piezoelectric motors and micromechanics should make it possible to create micromechanical systems that are small, inexpensive, and completely autonomous.<>