Mechanical Integration of a Sensorized Skin in an Anthropomorphic Hand: Design Pipeline and Tests

The ability to manipulate and grasp objects is largely affected by the tactile afferent provided by the skin in humans providing information that are used by the brain to guide motor actions. In the light of the recent advancements in neuroprosthetic, the quest for a hand prosthesis that integrate more sophisticated tactile sensor is increased. Electronic skin based on triboelectric phenomena holds significant promise in this respect, but the literature addressing its integration within a prosthetic hand is limited and scattered. Here we show a systematic and comprehensive pipeline for the design, development, and mechanical integration of a electronic skin. The paper addresses the identification of the technical requirements for the skin, the selection of material for the soft skin, and the definition of target contact area for optimizing the arrangement of 6 sensors within the size of a finger. After that, we discussed the design of the fingers for its integration and the manufacturing process. The proposed pipeline was validated through mechanical and electrical integrity tests. Compression tests applying 40 N demonstrate the e-skin's strength under realistic force conditions, and electrical tests show consistent sensors responses pre- and post- overload. Finally, we checked for activation of the sensors during the execution of three grasp types varying the size and the shape of the target object, to verify the arrangement of the sensors.