Microsoft filed a patent application covering a novel way to construct a “tactile” touchscreen. The idea is aimed at large table-sized computing displays such as the Microsoft Surface, rather than phones or tablets. If it could be used on smaller devices, it could spell the end of keypads on phones. Mobile keypads would simply be emulated when necessary. It is not yet known how feasible the idea is.
The display uses technical tricks to convince users they are actually touching the ridges, bumps and textures of a displayed image. Microsoft proposes producing a real texture, using pixel-sized shape-memory plastic cells that can be ordered to protrude from the surface on command. Creating well-defined bumps on a touch surface would enable touch typing at much faster speeds than on touchscreens today.
A projector built into the Surface displays a computer image onto the table top from below. As the user touches it, infrared reflections from their fingertips are detected by cameras beneath the table and used to pinpoint the position of the finger and lend touchscreen capability.
Microsoft proposes coating the display with a light-induced shape-memory polymer. This becomes hard and protruding when one wavelength of ultraviolet light is transmitted at a pixel, and soft when another wavelength hits it. By modulating these wavelengths, texture can be created. [Source: New Scientist]