A PZT Thin-Film Traveling-Wave Micro-Motor With Stator Teeth Based on MEMS Technology

The piezoelectric thin-film traveling-wave micro-motor based on the microelectromechanical systems (MEMS) process has the advantages of compact size, easy integration and batch production. However, the piezoelectric thin-film micro-motor still exits a serious shortcoming of very small output torque. This paper proposes a novel lead zirconate titanate (PZT) piezoelectric thin-film motor with stator teeth to improve the output torque. Firstly, theoretical analysis and finite element simulations were performed to determine the design parameters of the stator teeth. The device preparation is completed by combining with wafer-scale MEMS fabrication techniques, in which the base Si layer of PZT-SOI wafer is thinned and etched to form the stator tooth structure based on the deep reactive ion etching (DRIE) process. Finally, the performance testing results showed that the novel motor achieved a large output torque of $39.4 \mu \text{N}\cdot \text{m}$ under a low driving voltage of 4.5 Vpp. The large output torque is 2.65 times higher than that of the previously reported piezoelectric thin-film motor with a much higher driving voltage of 11 Vpp. [2023-0099]