Design, modeling, and analysis of a novel microgripper based on flexure hinges

A new 2-DOF microgripper, which can perform the processing of the objects assembly and biological cells injection, is designed and modeled in this paper. The clamping action of the microgripper with the x direction is completed, however, when anything is clamped by the end effector, which can be completely driven by an actuator generated in y direction, at last clamping and pushing motion are realized. The flexure hinge, which takes place of the conventional joint, is used as the translational and rotational hinges in the new structure. Otherwise, the whole microgripper is monolithic processing, which can efficiently overcome the disadvantages of the conventional hinge with friction, backlash, and errors caused by the hinge assembly. Firstly, a kind of novel microgripper is designed in this paper, which can accomplish two-dimensional independent motions including a separate grip and single track push without interfering with each other. The bridge type amplifying structure with two-end output is adopted in the gripper to increase the motion range and the capacity of the microgripper. The piezoelectric actuator with fast response and high resolution is used as the drive element. Secondly, the geometrical and kinematical models are established and the formulas of the amplifying ratio, stiffness, maximum stress, and the natural frequency of this model are calculated, respectively. Finally, the FEM (finite element modeling) based on ANSYS software is built up to validate the formulas.