article_snippet.sent: Through an emission of sound waves, sensations are projected through the air and to the user.
article_snippet.sent: Changes in air pressure are perceived as suspended tactile surfaces, creating invisible -- but tangible -- interfaces.
article_snippet.sent: To create their invisible buttons, UltraHaptics' use a small collection of ultrasonic speakers, concentrating the sound waves to a specific point.
article_snippet.sent: Sound travels through air by creating a pressure differential, so by focusing several of these differentials to a target location, the result is a single localized spot of high pressure.
highlights_snippet.sent: A tactile sensation is provided by ultrasonic waves, which alter air pressure .
  