A doorknob that knows whether to lock or unlock based on how it is grasped, a smartphone that silences itself if the user holds a finger to her lips and a chair that adjusts room lighting based on recognizing if a user is reclining or leaning forward are among the many possible applications of Touché, a new sensing technique developed by a team at Disney Research, Pittsburgh, and Carnegie Mellon University.

Both Touché and smartphone touchscreens are based on the phenomenon known as capacitive coupling. In a capacitive touchscreen, the surface is coated with a transparent conductor that carries an electrical signal. That signal is altered when a person's finger touches it, providing an alternative path for the electrical charge. By monitoring the change in the signal, the device can determine if a touch occurs.


Also: Learn more about a fiber-optic continuous liquid sensor.