Underwater Adaptive End Effector Based on Biomimetic Grasping Mechanism of Soft-Rigid Gripper

The underwater gripper serves as the end effector of underwater unmanned equipment, and its performance directly determines the effectiveness of the mission. Currently, commercial grippers are difficult to simultaneously meet the requirements of high load capacity and high adaptability, and it is hard to balance the dual demands of “non-destructive grasping” and “firm holding”. Inspired by lobster claws, this study proposed a novel biomimetic rigid-soft gripper, the “LobSTER Gripper”. It used a biomimetic reversed structure of soft fingers coated with rigid fingers: The soft fingers with passive compliance provided gentle initial contact, while internal rigid fingers ensured firm holding, enabling phased stiffness adaptation without complex drive control, it can also integrate visuo-tactile sensing at the base of the fingers to achieve precise perception and stable grasping of underwater targets. Experimental verification shows that the gripper achieves a 100% success rate in grasping in the pose disturbance scenario, significantly outperforming the traditional rigid gripper, which has an 80% success rate. The design offers a low-cost, reliable, and easily transferable solution for adaptive underwater grasping with significant engineering application value and promising promotion prospects.