Design, Modeling, and Optimization of a Novel Asymmetrical Piezoelectrically Actuated Microgripper

Abstract

Microgripper, as the end-effector of a micromanipulation robot, has been widely used in semiconductors, biomedicine, optical engineering, etc. The stack piezoelectric ceramic actuated microgripper has the advantages of fast response speed, high motion resolution, and good control performance. Traditional symmetrical microgripper has defects such as lack of positioning reference and dense modal of resonance. Therefore, it is necessary to develop an asymmetrical clamp with a large clamping stroke and good dynamic characteristics. This paper introduces the design, modeling, optimization, and simulation of a new asymmetric microgripper. The designed asymmetric gripper has the advantages of large-displacement magnification and high natural frequency. The gripper’s movable side is comprised of three-level compliant amplification mechanisms including bridge mechanism, Scott-Russell mechanism, and parallelogram mechanism. The linear relationship between the input displacement and the output displacement is obtained through motion modeling. The multi-objective genetic algorithm optimizes the major parameters of the structure which affect the clamping stroke. Finite element analysis is conducted to verify the clamping stroke, clamping force, and resonance frequency of the gripper. The simulation results show that the proposed microgripper has good working performance with a clamping stroke of 156.75 μm and a natural frequency of 952.91 Hz, which is promising for practical application.