A Novel Compliant Orthogonal Displacement Amplification Mechanism and its Application in Micro-Grasping

In the compact micro-grasping system, the combination of precisely orthogonal movement transformation, displacement amplification and simple structure is important. The typical solution of the combination issue requires bidirectional symmetric input forces/displacements. However, under a certain driving condition, numerous actuators used in micro-manipulation only supply unidirectional input froce/displacement for the driven mechanism, which makes the typical solution infeasible. In this study, a novel compliant orthogonal displacement amplification mechanism (DAM) is proposed to solve the combination issue for most of the actuators used in micro-grasping. The proposed mechanism is a triangulation amplification-based mechanism with undetermined structural parameters. The number of the undetermined parameters is analyzed. The equations satisfying the displacement boundary conditions and the equilibrium equations of the orthogonal movement transformation are derived to solve the undetermined parameters. Finite element analysis (FEA) of four design examples is used to verify the design method. The FEA results show that, for the design examples, the errors evaluating the orthogonal movement transformation are smaller than 0.56% and 0.15% respectively, and the displacement amplification ratios are larger than 4.6. The orthogonal displacement amplification is realized. Furthermore, a microgripper utilizing the proposed orthogonal DAM is presented. The performances of the gripper, including the displacement amplification and the parallel movement of the jaws, are verified by FEA.