Scientists in Germany have demonstrated an amazing new display with a surface that can physically change twice per second to act as a moving "tactile screen." Its potential for the blind or visually challenged is immediately obvious.
The display, made by a team at the Technical University in Dresden, is formed of droplets of hydrogel 300 microns across in a square array of some 4,200 pixels. Hydrogels are water-based colloidal gels used to make a variety of things from soft contact lenses, to smart wound dressings and breast implants, and one of their physical characteristics is their ability to change volume and mechanical strength.
The tactile display uses this to form the morphing pixels: As each spot (mounted on a black polyester substrate) is illuminated by a beam of light, it heats up. When its temperature goes above 35 degrees Celsius the spot loses some of its water and the gel contracts—losing about half its "normal" height of 0.5mm and becoming harder and more opaque. When the temperature drops, the gel absorbs the water back quickly and swells up again. By rastering the light-beam behind the display it's possible to render a high-resolution image that can switch every half second.
The team thinks the most immediate uses are for tactile displays for the blind, but there are potentials in many other domains: In surgery, surgeon's tools could give them tactile feedback on subtle changes going on at the tool tip; By moving shaped pixels in sequence, the morphing gel plate could act as a micro-pump for all sorts of applications; and it's easy to imagine tactile feedback on the controller of your game console to make a game like LittleBigPlanet even, well, weirder.
The team is working to improve the technology—to drop the activation temperature for one—but the display is not far from being practically useable. And since it's essentially very simple and requires components that are not overly expensive, it's the sort of tech you may end up seeing (or is that feeling?) in real products sooner than you may think.