Ultrasound tactile display for stress field reproduction - examination of non-vibratory tactile apparent movement

We developed a new tactile display using acoustic radiation pressure. The display can produce a 1 mm diameter focal point and 2 gf total force. By steering the focal point using a linear phased array, the display creates various precise spatiotemporal patterns of pressure distribution on the skin. We conducted experiments on "tactile apparent movement" with the tactile display and found that even if the successive stimuli were not vibrations but simple indentations, tactile apparent movement was evoked. When the intervals of the indentations were between 10 ms and 40 ms, discriminating between actual stroking and apparent movement was quite difficult.