SkinHaptics: Ultrasound focused in the hand creates tactile sensations

Recent developments in on-body interfaces have extended the interaction space of physical devices to the skin of our hands. While these interfaces can easily project graphical elements on the bare hand, they cannot give tactile feedback. Here we present a technology that could help to expand the output capability of on-body interfaces to provide tactile feedback without restricting the skin as an interaction surface. SkinHaptics works by focusing ultrasound in the hand using a phased array of ultrasound transmitters and the acoustic time-reversal signal processing technique. We present experimental results that show that this device can steer and focus ultrasound on the skin through the hand, which provides the basis for the envisioned technology. We then present results of a study that show that the focused energy can create sensations that are perceived under the skin and in the hand. We demonstrate the potential of SkinHaptics and discuss how our proof-of-concept device can be scaled beyond the prototype.