A Bioinspired Multi-Knuckle Dexterous Pneumatic Soft Finger

Dexterity is an essential characteristic of pneumatic soft grippers for robust grasping of objects. However, the traditional pneumatic soft grippers are difficult to grasp objects in a stable manner due to the inferiority of flexibility and stability. Inspired by the multi-knuckle structure of human fingers, a multi-knuckle pneumatic soft finger, composed of three independent-actuated segments, is proposed to enable a dexterous manipulation. Compared with the conventional single-chamber soft finger, the proposed soft finger possesses a larger travelling space (the maximum execution range of is 90.34 mm at x-axis), a tunable output blocking force and seven pneumatic controlling modes. Based on the multi-knuckle soft finger, a pneumatic soft gripper is constructed to perform a series of grasping demonstrations for different objects under distinct grasping modes. As a proof of concept, a 15-DOF anthropomorphic hand is fabricated using the soft fingers to mimic the human hand to express various gestures and play piano. As such, the multi-knuckle dexterous pneumatic soft finger maybe opens a new way to design dexterous pneumatic soft robots with stability and flexibility.