Design and analysis of a novel micro-gripper with completely parallel movement of gripping arms

The paper presents the design and analysis of a micro-gripper which has absolutely parallel movement of the gripping arms when it grasps or releases micro objects. By employing a compact displacement amplifier and several flexure supporting hinges, a novel gripper with simple symmetrical structure driven by piezoelectric actuators has been designed. The kinematics and dynamic modeling of the gripper are conducted by resorting to compliance and stiffness analysis based on matrix method, which are validated by finite-element analysis (FEA). Both FEA and the compliance/matrix model have well validated the movement of the gripping arms moving completely symmetrical parallel without any rotation, stretch or expansion. With the proper amplification ratio and the stroke of the PZT, the designed gripper has a large movement range, the displacement of the arms can reach 300μm, which has great potential in applications.