No more fumbling for light switches in the dark. By applying a layer of conducting paint researchers at the Disney Research lab in Pittsburgh, Pennsylvania, and Carnegie Mellon University have developed a cheap technology called Wall++ that converts walls into surfaces that can sense touch and swiped gestures . It can even detect what devices are being used in a room .

A conducting nickel-based layer is painted on as a grid and costs just $20 per square metre – roughly the same as low-cost …