A stick-slip piezoelectric rotary actuator with improved working bandwidth achieved by an asymmetric compliant mechanism (ACM)

Abstract

A large working bandwidth is beneficial for improving the output characteristics such as speed of stick-slip piezoelectric actuators. However, the form of frictional contact between the stator and rotor limits the improvement of the working bandwidth for the actuator. Therefore, this article proposes a stick-slip piezoelectric actuator using an asymmetric compliant mechanism (ACM) that can improve the working bandwidth by increasing the system stiffness under the same preload deformation. The asymmetric stiffness of left and right clamping arms was generated by the ACM, and the forces acting on the rotor at the right side would be larger than that at the left side. Accordingly, the rotor would produce a rotary motion. A prototype was fabricated and the output characteristics were tested under various driving voltages and driving frequencies. The experimental results indicated that the bandwidth of the proposed actuator is 89.3% higher than that of the traditional actuator with single clamping arm compliant mechanism. Simultaneously, the actuator could reach the driving speed of 1.22 × 105 μrad s−1. This study provides a new idea for improving the working bandwidth, and it is beneficial to broaden the application range of the stick-slip piezoelectric actuator.