(Credit: Disney Research)
Disney Research has created a method of providing tactile feedback from a flat touchscreen — by electrically shocking your fingertips.
Static electricity is usually experienced by humans in hilarious fashion, thanks to shuffling feet on carpet, rubbing balloons in hair and windy days. Pittsburgh's Disney Research, though, has another use for it: allowing the human hand to "feel" a textured surface through a flat touchscreen.
The team first examined how textures are usually perceived by the skin, determining that physical bumps are perceived when frictional forces stretch and compress the skin. "Our brain perceives the 3D bump on a surface mostly from information that it receives via skin stretching," said Disney Research director Ivan Poupyrev. "Therefore, if we can artificially stretch skin on a finger as it slides on the touch screen, the brain will be fooled into thinking an actual physical bump is on a touch screen even though the touch surface is completely smooth."
The next step was figuring out how to artificially simulate those frictional forces. To this end, the team used electrovibration — which Disney Research previously employed with TeslaTouch in 2010 — which uses static electricity to create an electric force field between skin and surface.
They were then able to tweak this force field using algorithms to create a texture map that matches the shape of the image displayed on the touchscreen, closely simulating the frictional forces felt by the finger when it slides over a real textured surface.
"Touch interaction has become the standard for smartphones, tablets and even desktop computers, so designing algorithms that can convert the visual content into believable tactile sensations has immense potential for enriching the user experience," Poupyrev said. "We believe our algorithm will make it possible to render rich tactile information over visual content and that this will lead to new applications for tactile displays."