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 commercially 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°, spatially and temporally. Then, a novel rotor structure, with protrusions on the contact surface, was designed and fabricated by silicon wet etching. 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, no extra force was applied to the rotor of our motor. The frictional force between the rotor and stator can be adjusted by changing the rotor weight and the protrusion configuration. It is shown that a rotation speed of up to 50 rpm under the exciting voltage 10 V was achieved