Supermarket shelves coated in foam could sense when they need restocking. Researchers at the Swiss Federal Institute of Technology in Zurich formed the coating by sandwiching a non-conducting foam between two layers of paint containing silver (Applied Physics Letters, ). When an item is lifted from a shelf, the foam expands, changing the capacitance of the coating.
Advertisers now have a fresh way to capture consumers鈥� attention: turn billboards into gesture-controlled video games. of Redwood City, California, has built an infrared camera system that sits on top of a giant LCD screen. It monitors the motion of passers-by up to 5 metres away, allowing them to play boxing and volleyball games with on-screen characters. The screens will appear this year in 150 Hilton hotels.
