Design and Optimization of a Multi-Mode Piezo-Motor Based on a Compliant Mechanism

Abstract Piezo-motors are widely used in precision positioning. However, the traditional piezo-motor moves via single motion mode such as stick-slip mode, inchworm mode, and scan mode, respectively. A single motion mode cannot balance motion speed, load capacity, and resolution at the same time. Integrating multiple motion modes into a piezo-motor is a sensible approach for conflict resolution. This paper presented a multi-mode piezo-motor based on a compliant mechanism that is able to regulate the contact force to achieve different motion modes. The characteristic of the compliant mechanism is analyzed by finite element method. To improve the performance of the proposed piezo-motor, the optimization design of the compliant mechanism based on the response surface method is carried out in ANSYS Workbench. A prototype, whose structure parameters were consistent with the optimization result, was fabricated. The performances of the proposed piezo-motor were tested through a series of experiments. The results showed that the prototype possesses a stiffness of 2.861N/um, and a fundamental frequency of 1203.8Hz, which are 37.8% and 11.9% higher than the initial design, respectively.