Effects of Longitudinal Skin Stretch on the Perception of Friction

This work focuses on the relative importance of skin stretch imposed on the fingerpad on the perception of friction. Perceptual data is presented from two separate tests. The first experiment was designed to determine the perceptual thresholds for friction based on a Karnopp friction model. In this experiment friction was rendered as purely a kinesthetic resistance via a PHANToM force feedback device. The second experiment was designed to evaluate possible changes in perceived friction magnitudes due to imposing small amounts of tangential skin stretch (0.25 - 0.75 mm) to the fingerpad in combination with force feedback (kinesthetic resistance). Results of this experiment show that even these small amounts of skin stretch increase the perceived friction. These results suggest that the addition of a simple shear plate tactile display to current haptic devices could significantly enhance the range of rendered friction since most current haptic force feedback devices have limited force capabilities