Touch sensitive displays have changed the way we interact with electronic devices everyday, evolving from single to multi-touch displays that can recognize multiple contacts. Now researchers at Disney Research, Pittsburgh, and Carnegie Mellon University have developed a touch sensitive technology called Touché that not only detects if and where someone is touching it, but how they are touching it.
Although Touché is based on the same capacitive touch sensing technology found in smartphone and tablet displays, instead of operating at a single frequency, it monitors capacitive signals across a broad range of frequencies. Called Swept Frequency Capacitive Sensing (SFCS), the technology makes it possible to detect not only when a surface is being touched or not but, by taking into account data such as the different capacitive properties of different body tissues, also the complex configurations of the hand or body that is touching it.
The researchers claim that SFCS is so robust that everyday objects could be enhanced with just a single sensing electrode. Additionally, already conductive objects, from a doorknob to the human body or a body of water, could act as a sensor.
Because Touché relies on analyzing hundreds of data points, it requires much greater processing grunt than a traditional touchscreen. However, the researchers say that microprocessors have now reached the required point in terms of power and price to make SFCS feasible for use in touch interfaces.
Just as touchscreens have made smartphones and tablets more intuitive to use, the researchers believe Touché could serve as an invisible control interface for the increasing numbers of embedded computers finding their way into our everyday lives. In addition to helping make everyday objects and materials touch and gesture sensitive, it could also enhance the touch capabilities of existing touchscreen devices, such as smartphones and tablets, by detecting the configuration of the hand.
"This might enable us to one day do away with keyboards, mice and perhaps even conventional touchscreens for many applications," said Munehiko Sato, a Disney intern and a Ph.D. student in engineering at the University of Tokyo.
The researchers have already developed a number of proof-of-concept applications, including a “smart doorknob” that can detect whether it is being grasped, touched with one finger or two, or pinched. This could allow the door to be programmed to lock or unlock using a “gesture password,” admit a guest, or play a message.
Another test application involved adding touch-sensing capabilities to the human body by having them. Using electrodes worn on both wrists that communicate wirelessly with a computer or mobile device using Bluetooth, the system was able to detect body gestures, such as touching fingers, grasping hands and covering the ears. Such movements could be used to control a mobile device such as a smartphone.
Attaching a single electrode to a water vessel also allowed the detection of gestures, such as the submerging of a fingertip or hand and the placing of a hand on the bottom of the vessel.
The research team will present its paper, “Touché: Enhancing Touch Interaction on Humans, Screens, Liquids, and Everyday Objects,” May 7 at CHI 2012, (Conference on Human Factors in Computing Systems), in Austin, Texas, where it has been recognized with a Best Paper Award.
The following video shows some of the Touché proof-of-concept applications developed by the researchers.