Optimizing Design of Piezoelectric Actuated Compliant Microgripper Mechanism

Pretty Khare, G. B. Madhab, C. S. Kumar, and P. K. Mishra

ABSTRACT: Compliant mechanisms have advantages of having no assembly joints and ease-of-manufacture. Optimal motion and force response of the mechanism depends on various parameters of the compliant mechanism and the actuation scheme used. This paper describes the design of a twofingered bio-inspired micro-gripper actuated by a pair of agonist-antagonist piezoelectric actuators. Coupled-field finite element analysis is carried out to optimize the design of a microgripper and its dimensions for maximum displacement gain and to obtain a relationship between the input voltage and output tip displacement. The design is optimized with respect to the hinge radius, position of the hinge, length of links, material concentration etc. Also volumes having almost zero stress concentrations can be removed to decrease the mass of the gripper. The paper describes a systematic study on the variations in design for good performance of the mechanism in terms of large displacements and improvements for areas of high stress, low strain etc. were suggested.

KEYWORDS: Design optimization, Micromanipulation and Compliant mechanisms

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