Design and Modeling of a 2-DOF Micro-Positioning Stage for Vibration-Assisted Polishing

To solve the issues of insufficient working stroke, low accuracy, and limited response time of stages for vibration-assisted polishing, a two-degree-of-freedom (2-DOF) micro-positioning stage is proposed in this paper. To compensate for the limited stroke of piezoelectric actuator, a bridge-lever amplification mechanism was designed to magnify output displacement. Based on Castigliano's second theorem and elastic beam theory, static modeling of amplification mechanisms, guiding beams, and transmitting rods was presented. Then, the analytical models of the stage were derived. To validate the accuracy of the analytical model, finite element simulations were performed, demonstrating that the error between theoretical and simulation results is 4.6%. Notably, the stage exhibits kinematic decoupling characteristics and excellent dynamic performances. The research results can provide effective insights for developing a large-stroke piezo-actuated micro-positioning stage with good dynamic performance for vibration-assisted polishing.