A Multi-Fingered Robot Hand with Remote Center of Motion Mechanisms for Covering Joints with Soft Skin

Robot hands are crucial for dexterous interaction with objects. The joints of existing robot hands typically cannot be completely covered with skin. This paper demonstrates a robot hand for which the palmar side of the joints, which is the side that is typically in contact with objects, can be nearly completely covered with a continuous, thick skin layer. This is possible with remote center of motion (RCM) mechanisms. Covering the palmar side of the joints with a thick skin layer has potential benefits for grasp stability, safety and allows the inclusion of tactile sensors in the joints in future work. A coupling mechanism is used in combination with the RCM mechanisms for the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints. Our evaluation shows that the hand can grasp various objects with different postures. The abduction/adduction mechanism, which is implemented in the metacarpophalangeal (MCP) joint in addition to the flexion/extension movement with an RCM joint, is demonstrated. It is further demonstrated that the RCM joints ensure that even thin objects that are grasped at the joints will make contact with soft skin.