Phase difference between normal and shear forces applied to fingertip can be discriminated in tactile perception of textures

Abstract

Tactile perception of textures have been explained by the properties of either of normal or shear forces induced between the fingertip and material during tactile exploration. However, we have found that the stochastic relationship between these two axial forces differ among textures in our previous studies. The phase difference between the two axial forces is one of the such relationship. To investigate whether the phase difference between the two axial forces affects the tactile perception of textures, in this study, we investigated the discriminabilty of the phase difference. We found that phase difference between two axial forces can be discriminated in roughness textures with large spatial wave lengths. This result can be applied to develop the method to present virtual texture by combining two types of tactile stimuli.