Design and analysis of a compliant microgripper with a large amplification ratio

This paper presents the design and analysis of a novel piezoelectric-actuated compliant microgripper that mainly consists of a three-stage amplifier and a pair of parallelogram mechanism to achieve a large amplification ratio and a wide motion stroke. The three stages are configured as two bridge-type with one lever-type amplification mechanism, and a pair of parallelogram mechanisms are integrated into the lever-type amplification mechanism to provide advantages in terms of parallel gripping and large amplification ratio. The crucial structural parameters are optimized by the response surface optimization. The static model of the microgripper is established and finite element analysis is conducted to evaluate the characteristics of the microgripper. The performance of the microgripper is investigated by experimental studies on a fabricated prototype. Experimental results show that the microgripper obtains a large displacement amplification ratio of 45.58, a wide motion stroke of 683.70 μm, and it can successfully grasp different copper wires with diameters of 300 μm and 500 μm.