‘Smart Doorknobs’ and Gesture-Controlled Smartphones
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.
Touché is a form of capacitive touch sensing, the same principle underlying the types of touchscreens used in most smartphones. But instead of sensing electrical signals at a single frequency, like the typical touchscreen, Touché monitors capacitive signals across a broad range of frequencies.
This Swept Frequency Capacitive Sensing (SFCS) makes it possible to not only detect a “touch event,” but to recognize complex configurations of the hand or body that is doing the touching. An object thus could sense how it is being touched, or might sense the body configuration of the person doing the touching.
SFCS is robust and can enhance everyday objects by using just a single sensing electrode. Sometimes, as in the case of a doorknob or other conductive objects, the object itself can serve as a sensor and no modifications are required. Even the human body or a body of water can be a sensor.
“Signal frequency sweeps have been used for decades in wireless communication, but as far as we know, nobody previously has attempted to apply this technique to touch interaction,” said Ivan Poupyrev, senior research scientist at Disney Research, Pittsburgh. “Yet, in our laboratory experiments, we were able to enhance a broad variety of objects with high-fidelity touch sensitivity. When combined with gesture recognition techniques, Touché demonstrated recognition rates approaching 100 percent. That suggests it could immediately be used to create new and exciting ways for people to interact with objects and the world at large.”