An application of SAW to a tactile display in virtual reality

SAW has great potential for a `tactile display´ in virtual reality which provides a human virtually with varied tactile sensation of roughness, textures, and friction. From an analysis of a sliding motion of a finger on a rough surface, it is shown that the parameters of the grain are directly related to a frequency of a stick-slip vibration of friction. Thus, it is necessary for the tactile display to create dispersed sources of shear stress which can be modulated temporally with the stick-slip frequency. In our tactile display, we explore a LiNbO<sub>3</sub> 128° Y-cut substrate with a `slider´ which has around 100 steel balls with the diameter of 800[μm] on a thin tape. Because friction between the substrate and the slider is reduced by generating SAW on the substrate, a virtual stick-slip can be created by a burst standing SAW with the carrier frequency of 15[MHz]. It is confirmed that the variable grain can be represented by controlling the burst frequency of SAW