A Novel Two-Stage Constant Force Compliant Microgripper

Abstract

The manipulating objects of the micron scale are easily damaged, hence the microgrippers, the key components in micro manipulating systems, demand precise force control, plus miniaturized size. Consequently, the constant force microgrippers, generally lack the ability to fit different sizes. To avoid the overload damage, apply multi-size microparts and simplify the control method, a novel two-stage compliant constant force microgripper is proposed in this paper. Based on the negative stiffness effect, this gripper is connected in parallel with a two-stage negative stiffness module and a positive stiffness module. Then, the elliptic integral method and the pseudo-rigid-body method are both employed to derive the kinetostatic and dynamic performances. Finally, the analytical results are validated. It is observed that two-stage constant forces of 1.33 N in 305.6 μm and 1.11 N in 330.8 μm are acquired.