Design and Development of a Rigid-Flexible Coupling Humanoid Dexterous Hand Based on Flexible Joints

The human hand has become one of the core objectives of bionic research due to its high degree of dexterity and versatility in grasping a wide range of tools and performing complex operations. The key to the dexterity of the human hand lies in the multiple degrees of freedom of its individual joints. However, most of the existing researches use rigid joints to achieve this goal, which, despite the enhanced dexterity, face many challenges in integration and lightweight design. In this paper, we propose a humanoid finger design based on flexible materials, employing flexible joints as moving parts, and develop a tendon-driven humanoid dexterous hand with multiple degrees of freedom. Through simulation and theoretical analysis, the flexible structure design applicable to the metacarpophalangeal joint is optimized and determined. Experiments show that the humanoid finger is capable of multiple degrees of freedom motion, and the performance of the dexterous hand is verified by Cutkosky taxonomy. The rigid-flexible coupling humanoid dexterous hand proposed in this study provides a novel solution for the design and development of humanoid hands.