A soft gripper integrated with mechanically-prestressed soft actuators

Soft robotic grippers can gently grasp fragile objects. However, it remains a challenge to grasp heavy objects, maintain the grasping states, and grasp objects quickly due to their low stiffness and high deformation. This study presents a soft gripper integrated with fluidic prestressed composite (FPC) actuators. Prestress is provided with a prestrained elastomeric matrix composite (EMC) to enable relatively high stiffness, precurved shapes, and maintain grasping states without energy consumption. Grasping test results show that the maximum grasping/self-weight ratio is 11.8 and the time for grasping a tennis ball nearby only takes 0.087 s. The gripper’s adaptability to objects is verified by grasping objects of different sizes and shapes.