A Large Range Constant Force Microgripper With a Three-Stage Compliant Amplification Mechanism

This paper proposes a novel piezoelectric actuated constant force microgripper with large gripping range for high precision micro-manipulation. The microgripper consists of a three-stage compliant amplification mechanism, a guide mechanism, and a constant force mechanism, enabling large displacement output and stable force output. The analytical model of presented microgripper is established using the elastic beam theory. Numerical simulations provided by finite element analysis (FEA) are carried out to verify the analytical model, and to evaluate the force and displacement characteristics of the mechanism with different gripping objects. Experimental tests are further implemented to validate the performance of the mechanism, and the fabricated microgripper can grasp objects with a constant force of 0.3N in a large displacement interval ranging from
$65~\mu \text{m}$
to
$130~\mu \text{m}$
under a voltage application of 100-V. The results of simulation and experiment clearly demonstrate that the constant force microgripper has a large work stroke, allowing effectively gripping objects in various sizes and stiffnesses.