A Universal Gripper Using Optical Sensing to Acquire Tactile Information and Membrane Deformation

The universal gripper has attracted attention due to its simple structure and advanced grasping ability for irregularly shaped objects. In this research, we propose a novel design for a granular-jamming-based gripper which uses a transparent filling and a semi-transparent membrane to allow optical sensing to detect both deformation of the membrane and the object being grasped. By adjusting the refractive index of an oil mixture to the refractive index of the granular bodies, we produced a fully transparent filling that allows the use of a camera inside the universal gripper. In this paper, we present the materials and development of our prototype, and describe the experimental confirmation of the prototype's performance. We showed that our prototype was able to grasp cylindrical and rectangular objects between 10 to 70 mm length while also tracking the deformation of the gripper.