Design and analysis of adaptive compliant grippers with passive finger structure

The adaptive compliant gripper with passive fingers can achieve both a more compact structure and better application versatility. However, the conceptual design of passive fingers is difficult and lacks relevant design method. To solve this problem, this paper proposes an active-deformation-aided strategy for the topology optimization of passive finger structure. This strategy utilizes an auxiliary input force to enlarge the output deformation and enable feasible synthesis of passive fingers. The influence of virtual spring stiffness on the optimization results is studied. Based on two designed passive fingers, two compliant grippers are developed to further evaluate their grasping performances. The designed grippers are verified by finite element analysis and experiments, and compared with the fin-ray effect gripper. The results show that the designed passive grippers exhibit excellent adaptability and grasping performance. This paper provides two novel structures of passive finger. The proposed design strategy can facilitates the design of the adaptive grippers with passive finger structure.