A novel piezo-driven microgripper with a large jaw displacement

This paper presents a novel piezo-driven microgripper for micromanipulation. A two-grade amplification mechanism is introduced to enlarge the jaw displacement of the microgripper driven by a piezoelectric actuator (PEA). The design adopts a hybrid flexure structure that integrates flexure hinge and flexure beam to combine their advantages to further improve the microgripper performance. The mechanical designs of two microgrippers with different output manners are first described, one of which is selected to conduct the detailed modeling and analysis. Subsequently, the finite element analysis (FEA) is performed to verify the microgripper performance and the effectiveness of the established models for the investigation of optimum structure parameters. Finally, after the prototype is fabricated, the experimental results show that the developed microgripper possesses the high-precision grasping capacity for different shaped and sized microobjects. Moreover, a large jaw displacement of 150.8 μm corresponding to the 100 V drive voltage and a high amplification ratio of 16.4 can be obtained.