Influence of the skin thickness on tactile shape discrimination

Tactile sensors are important for robotic or prosthetic hands, which are designed for manipulation of objects. These sensors are normally embedded in soft, elastic materials for protecting the subsurface sensor from damage or for better hand-to-object contact. In this paper, various thicknesses of the synthetic skin were investigated to determine their effects on the signals that will be detected by the embedded sensor. A finite element model of an artificial fingertip, which was based on viscoelastic and hyperelastic behavior, was used. It was shown that the synthetic skin blurs the signals that are transmitted to the embedded sensor. In short, the thicker the material, the more it will be difficult for the embedded sensor to discriminate the shape that is indented on the surface. These results are helpful to guide the specifications of the skin thickness of artificial skins with embedded tactile sensing.