Preliminary study on the difference of fingertip skin deformation between radial and ulnar side

Abstract

The stick-slip phenomenon occurs in dynamic friction plays an important role in haptic perception. We observed that when using the finger pad to interact with a rough surface, under a certain downforce, the stick-slip phenomenon is more likely to occur when the finger exploring in ulnar direction than radial direction. We speculated that this might be the result of the different deformation characteristics of the skin on both sides of the finger pad. In this paper, we performed 3D measurements to obtain the height information on both sides of the fingertips under different downforce and tangential force. The results showed the differences in the elastic properties of the skin, which may explain the direction-depended stick-slip phenomenon.