A Stator Design of Traveling-Wave Ultrasonic Micromotor

With the development of Microelectromechanical systems technology, piezoelectric traveling-wave ultrasonic micromotor has been widely used in micro equipment due to excellent performance, such as high-density output, high torque at low speed. A stator structure of ultrasonic motor working under the B 15 mode is analyzed and designed, which consists of a ring Si substrate of 3mm in radius, twenty Lead zirconate titanate (PZT) blocks and twenty supporting beams. The finite element simulation results show that the structure can generate two nearly symmetrical standing wave modes with a quarter wavelength difference in phase, and has a high quality factor (Q), so the micromotor can be driven by synthesizing high quality traveling-wave from the two standing waves, and can control the rotate speed through the drive voltage.