Universal jamming grippers for deep-sea manipulation

In this paper, we demonstrate the first underwater use of a `universal jamming gripper' to successfully grasp irregularly shaped objects. We present several novel developments which are required to extend this soft robotic technology to underwater operation including the use of pressure tolerant glass spheres and liquid water as the jamming media; an `under-filling' technique to achieve effective grasps without requiring a rigid substrate; and the use of internal ball chains to increase maximum lift capability without excessive deformation. We present data indicating that canonical shapes can be grasped with less downward force applied than previous jamming gripper designs. Finally, the feasibility for use on ROVs is demonstrated through use with inspection- and micro-ROVs in a test tank.