The Conformance Test for Robotic/Prosthetic Fingertip Skins

Although the requirements for robotic and prosthetic skins may considerably differ, conformance is a critical property when a tactile sensory system is embedded on the skin. The skin's inability to deflect or adapt to the surface of an object will prevent the spatial features to be transmitted to the embedded tactile sensors. By characterizing viscoelastic materials like Technogelreg, silicone and polyurethane, and applying their material coefficients to a finite element model, comparisons were made possible with the experimental surface deflection of a human fingertip that was indented by a wedge. Simulations showed that the silicone as the inner layer, and polyurethane or Technogelreg as the outer layer offered the optimal combination that approximates the human fingertip's conformance