A Flexure-Based 2-DOF Microgripper for Handling Micro-Objects

Abstract

In this paper, a new Piezoelectric Actuator (PEA) microgripper with two degrees of freedom (2-DOF) is proposed for grasping and micro-positioning of micro-objects. It incorporates two types of parallel mechanism, namely, flexible and rigid body based. The flexure-based gripper is intended to improve the dexterity and flexibility of the grasping and release of micro-objects. Finite Element Analysis (FEA) was employed to evaluate the performance of the microgripper's design parameters. The workspace of proposed mechanism was obtained using a kinematic model. The FEA results showed that the maximum stroke of grasping and transferring are 476 11m and 88 11m, respectively. The displacement amplification ratios are 15.87 and 2.93 for grasping and transferring, respectively. In the worst-case scenario, the maximum equivalent (von-Mises) stress and minimum safety factor of the designed microgripper were obtained as 3.83 MPa and 13.1, respectively, this confirms that the microgripper performs well without any failure. The concept of inverse kinematics was implemented on the proposed mechanism in FEA model and utilized to investigate the mi-crogrippers motion and coupling effects. Computational results indicated that the proposed 2-DOF microgripper can achieve accurate motion trajectory during grasping and releasing micro-objects.