A Novel 2-DOF Piezoelectric Stick-Slip Actuator With Parallel Guiding Decoupling

This article proposes a two-degree-of-freedom actuator based on the stick-slip motion principle to meet performance requirements of macrostroke, nanoaccuracy, and few coupling in the micro/nanooperation field. Unlike existing 2-DOF stick-slip actuators, it exhibits a compact decoupled parallel guiding structure in macrostroke. The actuator mainly consists of decoupling, driving, and preloading units. The decoupling unit uses parallel kinematic chains with guided rails and connectors to decouple macromovements, the driving unit utilizes bridge mechanisms to amplify single-step displacement, and the preloading unit adopts flexible hinges to adjust contact friction, thus performing well. Then, theoretical analysis and electromechanical simulation are performed. A prototype is finally fabricated, and motion performance tests are conducted. Experimental results show that the net single-step displacements in the x- and y-direction are 37.08 and 36.63 mu m, the coupling ratios in the two directions are 0.75% and 0.77%, and the displacement resolutions are 6.4 and 7.3 nm, respectively. Meanwhile, the motion stroke can be up to 13 mm x 13 mm. Also, the actuator has a maximum speed of 13.97 mm/s and a maximum vertical load capacity of 50 N at a drive voltage of 120 V. Experiments verify the superior performance of the 2-DOF decoupled stick-slip actuator.