Achieving Stable and Effective Stick-Slip Motions of Piezoelectric Actuators With a Small Mass Rotor by Means of the Auxiliary Friction

Stick-slip piezoelectric actuators are favored by precision instruments owing to their high resolution, fast response, etc. However, they face challenges when it comes to achieving effective output of the actuators with small mass rotor due to the offset of the forward angle by the backward angle. Aiming to achieve stable and effective stick-slip motion, a method that employs auxiliary friction was proposed, and accordingly, a stick-slip actuator was designed. Then, the feasibility of the auxiliary friction method was proved by comparing the theoretical analysis results of the output performances for the actuator with and without auxiliary friction. An experimental prototype with the rotor mass of 2 g was developed to test its output performances. Under 10 Hz and 100 V, the actuator with auxiliary friction exhibited a top torque of 3.85 N·mm, which was 55 times that of the actuator without auxiliary friction. Moreover, the actuator demonstrated a resolution of 1.2 μrad and a speed of 367.5 mrad/s. Experimental results showed that the auxiliary friction method could assist the actuator in achieving stable and effective stick-slip motion, thereby broadening its practical applications.