A Bridge-type Piezoelectric Microgripper with Integrated Position/Force Sensors

Microgrippers play an important role in micromanipulation and microassembly tasks. Based on the bridge-type mechanisms and parallelogram mechanisms, a compliant piezo-driven microgripper is designed in consideration of its demand for large gripping ranges, parallel movements and integrated position/force sensors. According to mechanical principles and compliant mechanism theory, the theoretical amplification ratio, natural frequency and output coupling ratio of the microgripper are derived. Then, the ANSYS software is used to simulate the amplification ratio, natural frequency and output coupling ratio of the microgripper. Finally, an experimental system is set up to verify the performances of the microgripper. The experimental results demonstrate that the microgripper has a gripping range of 0.345μm~328.2μm, an amplification ratio of 16.4 and a natural frequency of 157.5 Hz. The relative errors of the amplification ratio and the natural frequency between ANSYS simulations and experimental results are 17.7% and 12.9% respectively. The validity of theoretical models and ANSYS simulations are proved by experimental results, and the design objectives of large gripping ranges, parallel movements and integrated position/force sensors are achieved.