'Touche' gives human touch to doorknobs, 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 on her lips are among the many potential applications of 'Touche', a new sensing technique.

Touche, developed by Disney Research and Carnegie Mellon University, 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, Touche 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, according to a Disney statement.

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, Touche 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," said Poupyrev.

Besides Poupyrev, the team included Chris Harrison, doctoral student in Ernegie Mellon's Human-Computer Interaction Institute and Munehiko Sato, Disney intern and doctoral student in engineering at the University of Tokyo.

They will present their findings on Monday at CHI 2012, the Conference on Human Factors in Computing Systems, in Austin, Texas, US.