Design of large-displacement asymmetric piezoelectric microgripper based on flexible mechanisms

The output displacement of the traditional symmetrical microgripper is large, but its micro-components or parts are easily damaged due to the uneven force exerted on the left and right jaws of the gripper. The output force of the traditional asymmetric microgripper is stable. However, its output displacement is small, typically half the output displacement of the symmetric microgripper. To solve these problems, in this study, we designed a large-displacement asymmetric microgripper. First, we calculated the relationship between the theoretical input and output variables based on their geometric relationship. Then, we analyzed the performance of the microgripper using finite element software. Lastly, we used a piezoelectric actuator as the input driver of the microgripper. The errors associated with the theoretical and simulated output displacements were 7.05% and 9.24%, respectively. At 150 V of driving voltage, the maximum output displacement was 224 μm, and the actual magnification was 11.2 times. Microparts can be gripped in parallel and stably, which confirms the validity of the design.