Design, analysis and experimental performance of an integrated linear-rotary piezoelectric actuator based on inertial stepping principle

Abstract

This study proposes an integrated linear-rotary piezoelectric actuator based on inertial stepping principle. By employing a specially designed Z-shaped flexible structure and connector, the actuator can achieve linear and rotary motion outputs within a compact space using just two piezoelectric bimorphs. An actuator prototype is fabricated and tested. The actuator prototype can produce stable linear and rotary motion outputs, with high repeatability for each step. For the linear motion, the resolution is about 53.2 nm. At 120 V_p-p and unloaded conditions, the maximum linear velocity reaches 462 μm/s at 50 Hz. At 120 V_p-p and 1 Hz, the load capacity and return deviation are 230 g and 183 nm, respectively. The coupled angular displacement during five linear steps is approximately 0.0109 mrad at 120 V_p-p and 1 Hz, in an unloaded condition. For the rotary motion, the resolution is about 1.144 μrad. At 200 V_p-p and unloaded conditions, the maximum angular velocity reaches 5.2 mrad/s at 40 Hz. At 200 V_p-p and 1 Hz, the load capacity and return deviation are 265 g and 102.77 μrad, respectively. The coupled linear displacement during five rotary steps measures approximately 47.6 nm at 200 V_p-p and 1 Hz, in an unloaded condition. The proposed actuator integrates multiple superior characteristics such as large working range, high resolution, no drive redundancy, compact structure, and two-degree-of-freedom (2-DOF) motion outputs. These features highlight the significant application potential of the proposed piezoelectric actuator across multiple domains.