An Optimal Geometric Design for a Four-stage Compliant Microgripper Using a Hybrid Algorithm

High precision micro-manipulation is currently in great favor due to increasing applications and recent advances in microscale technologies. As microgrippers are the principal means of conducting micro-scale operations, they significantly affect the procedure's quality and output. This paper presents a novel optimized design of a compliant microgripper intending to improve capability and endurance. A compact flexure-based mechanical structure with four stages of displacement amplification mechanisms has been selected as the main frame of the proposed microgripper. A full factorial Design of Experiments (DOE) is not an efficient investigation approach when a large number of parameters are analyzed, and they are not presumed to behave linearly. Thus, a plan of experiments based on L۲۵ orthogonal array was established. The experiments were conducted using the Finite Element Method (FEM) in Abaqus ۶.۱۴ Workbench. The microgripper's range of motion and the maximum stress created by the actuation are selected as two crucial goals for the optimization process. A set of designs is offered and using the proposed algorithm, and the choice can be made regarding specific utilization necessities. Analytical Hierarchy Process is the decisive component of the selection method, ensuring efficiency and clarity. The presented design method of piezoelectric microgrippers shows excellent potential for customizing them for particular applications.

Keywords:

Microgripper , Compliant mechanism , Multistage amplification , NSGA-II