Tactile rendering of 3D features on touch surfaces

Abstract

We present a tactile-rendering algorithm for simulating 3D geometric features, such as bumps, on touch screen surfaces. This is achieved by modulating friction forces between the user's finger and the touch screen, instead of physically moving the touch surface. We proposed that the percept of a 3D bump is created when local gradients of the rendered virtual surface are mapped to lateral friction forces. To validate this approach, we first establish a psychophysical model that relates the perceived friction force to the controlled voltage applied to the tactile feedback device. We then use this model to demonstrate that participants are three times more likely to prefer gradient force profiles than other commonly used rendering profiles. Finally, we present a generalized algorithm and conclude the paper with a set of applications using our tactile rendering technology.