A Two-Finger Soft Gripper Based on Bistable Mechanism

Soft grippers are widely studied and utilized in soft robotics owing to their advantages in terms of compliance, safety, and adaptability. Limited by the mechanical design and driving methods, their response speed is usually unsatisfactory. To achieve fast and safe grasping, a novel design scheme for a two-finger soft gripper is proposed. The two fingers are tendon actuated and employ two types of bistable mechanisms for quick response and linkage bending. The geometric relationship between the thumb and length of the hyperelastic rings was analyzed in the bending process, from which a potential energy model was established. A high-speed camera was used to capture the movement of the gripper, and it indicated that the grasping process time was less than 0.2 s. Moreover, the gripper can grasp various objects, including fragile and irregularly shaped items. Consequently, the current soft gripper can integrate speed, safety, and compliance through simple mechanical designs.