Abstract: Fingers are the basic components of anthropomorphic hands. At present, most anthropomorphic fingers utilize rigid joints, which have obvious fabrication and assembly complexities as well as limited flexibility and adaptability. Thus, some anthropomorphic fingers were attempted to utilize compliant joints learned from bioinspiration, but they have a limited self-resetting ability and lateral deformation resistance, as well as occupying a large space and having a non-anthropomorphic appearance. In this paper, nine compliant joints for anthropomorphic fingers were analyzed using Finite Element Analysis (FEA), based on which two combined compliant joints were proposed, and the optimal one was obtained through FEA and experiments. An anthropomorphic finger that embeds parts of the compliant joint into the adjacent phalanxes was then designed. Finally, the anthropomorphic finger was fabricated and experiments were conducted. Experimental results show that the anthropomorphic finger with the proposed combined compliant joints has a better self-resetting ability and lateral deformation resistance while ensuring a large range of motion similar to that of the human finger, and the required actuating force is reasonable. Furthermore, the embedded joint structure can reduce the occupied space of the joint so as to improve the anthropomorphic appearance of the finger, and enhance its lateral deformation resistance.

Key words: anthropomorphic finger, compliant joint, deformation, stress, bioinspiration