The staff of the University of Washington in Seattle (USA) showed the world a fairly inexpensive way by which you can give an ordinary screen, the ability to recognize touch.
The technology is based on effect of interference of electromagnetic waves. With the help of a five-dollar sensor that receives power from the electrical outlet, the system measures the level of signal emitted from the liquid crystal panel. The data then processes the special software that identifies characteristic changes when approaching hands.
The authors showed how to use the technology, for example, to control media player, zoom Windows, and perform other simple actions.
Alas, the system is not able to provide the same precision as touch screens of modern smartphones and tablets. Impossible and implementation of complex gestures like pinch-to-zoom (zoom with two fingers).