Gel-filled touchscreen creates real buttons on demand

There's just something about the feeling of physical keys that haptic feedback simply can't replicate on touchscreens. It's part of the reason people buy keyboard accessories for tablets, or Ryan Seacrest's strange iPhone case. It's also inspired some to try to figure out a happy medium between the freedom of touchscreens and the tactile joy of real buttons. Tactus' fluid pocket approach showed promise (the company makes an iPad case that gives the on-screen keyboard a physical presence), but it's ultimately limited by a predefined layout. Now, though, a group of researchers at the Technische Universität Berlin have come up with a way to create soft, temporary buttons of pretty much any shape and size, anywhere on a touchscreen display.

To make this magic happen, the researchers are using a heat-activated gel that's transparent and fluid at room temperature, but hardens into an opaque, defined shape when warmed. The team's "GelTouch" 7-inch prototype is fronted by a layer of this gel, with another layer of conductive film behind that. The film carries electrical current (and therefore heat) to discrete areas of the display, creating a variety of button layouts -- proof-of-concept patterns include a rectangular key arrangement, a slider (albeit made from a row of the same keys), and a joystick-like nub. (You can check out a video of the team's work here.)

The GelTouch prototype isn't exactly polished, but the researchers imagine the technology being used not only to bring tactile feedback to flat displays, but also where "feeling" your way around a touchscreen would be beneficial -- on a car's infotainment system, for example, so you can keep your eyes on the road. There are plenty of issues that still need to be overcome, however. For starters, the gel requires constant power to stay "activated," and there's a lag period of a few seconds between soft and hard states. Also, the gel isn't transparent when it takes on a distinct form, so you might have trouble typing on a keyboard, for instance, when you can't see the letters behind white blobs of the hardened material. Still, it's certainly an interesting concept, and who knows? One day we mightn't need to choose between the clean face of an all-touchscreen smartphone, and the typing prowess of a BlackBerry.