Adding Texture to Aerial Images Using Ultrasounds

We present a method to add textures to aerial images using ultrasounds. The superposition of an acoustic radiation pressure on an aerial image allows users to feel a tactile texture of a virtual object floating in midair. Tactile textures can be altered by modulating the waveform of the ultrasounds. The tactile feedback is presented selectively on the user’s fingertip using an infrared sensor without an extra marker. The proposed method provides a rich visuo–tactile experience all in free space.