Disney Research recently showed off a project called Aireal, which adds physical sensation to virtual interactions like the Microsoft Kinect. It uses puffs of directed air to give you the sensation you're actually touching something you see on the screen. Now they've moved on to touchscreens in what seems like a no-brainer follow-up: Adding texture to touch.
Disney Research has developed an algorithm for the "tactile rendering of 3D features" on a 2D touchscreen. In other words, the algorithm modifies the friction between your finger and the 2D screen based on the slope of the virtual surface. If there's a dome on the screen, for example, increased fiction would, to some extent, make it feel like your finger was climbing or passing over a bump.
The algorithm modifies the voltage of the display to alter its friction, so different textures will produce a different feeling for your hand. Disney says it can reproduce ridges, edges, bumps, protrusions, and other physical sensations. And this isn't some funky touchscreen way to "fake" the sensation of touch. No, you're not actually feeling a virtual object, but this is how our sense of touch works to begin with.
"The algorithm is based on a discovery that when a person slides a finger over a real physical bump, the person perceives the bump largely because lateral friction forces stretch and compress skin on the sliding finger," says Disney's press release. The best part is, the algorithm is dynamic, which means it can produce varying touch sensations on the fly. No pre-programmed libraries of textures to apply to millions of objects.
Some of the immediate applications are pretty cool to think about--touchscreen games could go to town with this added element of feedback, and textured topographic maps of anyplace in the world would be great learning tools for kids. The Disney video below shows their algorithm being used in plenty of other situations, too--helping the blind, touching a cactus (why would you ever want to do that?), and they say it could be integrated into future touchscreen displays. Cost and simplicity are big question marks there, but it would be pretty wild if every touchscreen provided textured feedback five years down the road.