“Eyes-free” mobile phone dialing may be a not-too-distant reality. Hot on the heels of Google recently announcing its experimental Android powered interface comes this prototype from Carnegie Mellon University featuring pop-out buttons on a touch-screen which allow you to tap away without keeping a close eye on the screen.

Graduate student Chris Harrison and Professor Scott Hudson have developed several prototype displays featuring tactile pop-out buttons for certain functions. Basically, the prototypes involve creating an air chamber by layering several specially cut pieces of clear acrylic, on top of which is draped a thin sheet of semi-transparent latex. This latex acts as a pliable, deformable projection surface. The air chamber, connected to a pump, is either negatively or positively pressurized to create small concave or convex pop-up buttons that copy the feel of actual physical buttons. (See gallery for diagram).

Underneath, a camera senses Infrared light being scattered by fingers touching the surface of the interface, while rear projection casts images onto the screens.

Although similar systems have been explored in the past, according to Harrison their displays are the first to be touch sensitive as well as combining pop-up buttons and the display of dynamic information. He goes on to say that although several other touch screen displays made of glass or rigid plastic are able to register pressure, what sets this model apart from others is that it offers tactile feedback.

As with previous “eyes-free” developments, the technology promises to be a useful application for those who don’t want to or can’t concentrate on a task on the screen. The researchers are currently looking at ways to shrink their current prototype, as they concede that “you can’t get a pump inside a cell phone”.

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