Micromachined piezoelectric traveling wave micromotors for intelligent systems

This paper described a new type of thick films piezoelectric rotary micromotor, whose stator is made from a commercial available piezoelectric membrane composed of a copper substrate to which piezoelectric ceramics PZT thick films are bonded. This micromotor was driven by the traveling wave formed by the combination of two standing wave natural flexural waves whose phases differ by 90 degrees, spatially and temporally. Then, a novel rotor structure, with protrusions on the contact surface, had been designed and fabricated by silicon wet etching. And the stator was obtained by standard photolithography. Next, using the power source we developed, some properties of the micromotor were measured and analyzed. Unlike the other motors, for our motor no extra force was applied to the rotor. The frictional force between the rotor and stator could be adjusted by changing the rotor's weight and the protrusion's configuration. Our works had shown that the rotation speed of the motor was up to 50rpm under the exciting voltage 10V. By choosing the appropriate configuration of the motor, we can adjust the working frequency, rotation speed and other properties properly.