A topology optimization method and experimental verification of piezoelectric stick–slip actuator with flexure hinge mechanism

This paper presents a topology optimization method to design the piezoelectric stick–slip actuator. In particular, the vertical input displacement can be converted to the oblique displacement by the flexure hinge driving mechanism, and the large-stroke motion is realized. Based on the solid isotropic material with penalization (SIMP) model and combined with the motion characteristics of the stick–slip actuator, in order to obtain a larger output displacement and limit the parasitic displacement, the ratio of output displacement to input displacement is maximized as the objective function, and the relationship between parasitic displacement and output displacement is considered as a constraint condition. The method of moving asymptotes (MMA) is used to solve the optimization problem, and the driving mechanism structure is designed by the topology optimization result. The feasibility and reliability of the driving mechanism are verified by finite element analysis (FEA), then the prototype is fabricated. Experimental test results indicate that the velocity of the actuator reaches 15.25 mm/s under the locking force of 1 N and frequency of 650 Hz, and the resolution of 96 nm is achieved. This work shows that the topology optimization method can be used to improve the performance of the actuator.