All three groups have filed patents for electrovibration; each outlines a different approach. Currently, the Disney demonstration only provides the feeling of texture when a finger is moving, although the group is working on a way to give feedback to a still finger. Senseg’s technology, however, already provides localized feedback to a nonmoving finger, says Ville Mäkinen, founder of the company.
Another limitation of the Disney prototype is that it provides only a single sensation at a time. However, it is possible to split up the screen in various ways to generate different sensations in different parts of the screen, but the design of such a screen would most likely depend on the specific application.
Nokia is exploring ways to use the tactile feedback as a way to augment communication with another person, says Tapani Ryhänen, Nokia lab director in Cambridge, UK. “There’s a possibility to use this as a type of communication,” he says, “so if I do something on my screen, then you can feel it on your screen.”
While electrovibration can provide a different feel for touch screens, the type of interaction is somewhat limited, says Bic Schediwy, director of research at a touch-screen company called Synaptics. Since some systems only work when a finger is moving, those systems couldn’t simulate a button click, one of the biggest complaints with touch screens. Additionally, he says, in demonstrations of electrovibration systems, it appears that people have varying responses to the induced current, possibly because of varying skin thickness.
At the UIST symposium, the Disney researchers showed a range of demos to illustrate TeslaTouch, including a simulated ice-covered window that changes friction as virtual ice is removed and a racetrack that provides different sensation as a finger traverses varying terrain. On hand to test the system was Patrick Baudisch, professor of computer science at the Hasso Plattner Institute in Potsdam, Germany. While the demos were simple, he says, they were “very convincing.” TeslaTouch may not provide “the basis for getting rid of keyboards or such,” Baudisch says, but “it really enriches the interaction on touch devices.”
Disney’s Poupyrev isn’t sure about what his company plans to do with the technology, but the applications that are most obvious involve honing electrovibration so it could be used to more easily draw and paint on a smooth touch surface. Poupyrev also thinks electrovibration, since it is so easily implemented, could find a home in more unusual applications, such as large surfaces like wallpaper, and conformable materials like cloth.