Image via Senseg / The Economist
"THE smooth and impenetrable surface of the touchscreen has become familiar to everyone from dexterous toddlers to frustrated, fat-fingered adults. But not for much longer if Ville Makinen, the founder of Senseg, has his way. Under Dr Makinen’s tutelage Senseg, a Finnish firm, is deliberately roughing touch screens up. It is applying the idea of haptics—feedback to the sense of touch, rather than the senses of vision and hearing that are the usual targets of computer interactions—to the interface between screen and user.
A standard touchscreen employs what is called capacitive sensing to respond to a user’s prods. The electric charge held by a capacitor can be affected by a nearby conductor. Since fingers are conductive, they have this effect. An array of capacitors underneath the transparent cover of a touchscreen can thus locate an approaching digit, causing the device’s software to react accordingly.
Senseg’s “feelscreens” reverse this process. By applying a proprietary coating to the screen and varying the electrical charge in it, that screen can be made to attract or repel the flesh of a touching finger. The electrostatic force involved is small (think rubbing a balloon on your sleeve, and then sticking it to a wall), but it is enough for the nerve-endings in a fingertip to detect. Modulate the force appropriately and you can induce a feeling of sandpaper, corrugated iron or fabric. You can create the perception of raised keys on a screen, even though it remains flat, or of an e-book’s pages actually feeling like paper. You can even make the features on a map stand out to the touch, allowing the blind, as well as the sighted, to navigate." via The Economist