Multisensory Integrated Dexterous Finger With Coupled-Adaptive Features

The coupled-adaptive movement of the human finger enables the formation of a hull around an object during grasping, thereby simplifying brain control. Notably, the existing dexterous hands, represented by coupled fingertips and middle phalanges, demonstrate limited adaptability. This article introduces mechanical compliance to this finger design, developing an integrated multisensory robotic finger. The finger's primary feature is its capacity to actively switch the movement forms of both end joints to cater to different task requirements. Mechanical compliance ensures the stable grasping of various objects during a power grasp, reducing the need for planning and control methods. During precision grasp, the mechanism shifts to a coupled mode for exact fingertip position and force control. We analyzed the underactuated finger's stability and compliance, followed by the development of a multisensory finger prototype, which integrates a low-level control system into its mechanical structure. The finger's performance underwent testing through a series of experiments. Results indicate that the finger demonstrates robust object adaptability, dexterous manipulation capabilities, and higher load capacity. Moreover, the joints present the features of both self-locking and backdrivability.