Bioinspired Pad and Claw Composite Structure for Soft Robot Grasping and Crawling

Abstract

The meat pads and claws serve as crucial functional components of cats' paws, which together enable the paws to exhibit remarkable dexterity. Inspired by extension and retraction of cat's claws, we have designed a composite structure combining pads and claws that can switch between pad state and claw state for soft robotics applications. This structure is mainly composed of belts and pads equipped with a claw array, thereby forming the inner and outer coils and being driven by two motors. The outer coil is mainly used to change the forward and backward swing angle of the structure, while the inner coil is mainly used to switch the state, that is, to extend and retract the claws. The kinematics of the structure and the contact point model of the claw are established, the bending curve of the pad is fitted by an algorithm, and the overall mechanical properties of the structure during objects contact are discussed. Finally, we designed a gripper and a quadruped robot based on this structure, and experimentally verified that the novel composite structure based on pads and claws can significantly enhance the adaptability of soft robots to different tasks.