Charging systems that don't require our devices to be plugged in are becoming more and more normal, but often require things like smartphones to be in very close proximity in order for the technology to work says New Atlas writer Michael Irving. But a new paper outlines how an LCD-like panel could be used to charge several devices simultaneously from a distance of up to 10 meters (33 ft). Irving explains:

Current systems mostly work through induction. The charging panel contains a coil of wire, and as a current flows through that coil, it generates a magnetic field strong enough to induce a similar current in a nearby coil – say, one that's incorporated into a phone, toothbrush or electric car. The problem with these is that the strength of that magnetic field drops off very quickly, meaning the device needs to stay in contact with, or at least very close to, the power source. The upshot is that while there's no need to actually plug in, you're still effectively tethered to the charging source.

"Our proposed system would be able to automatically and continuously charge any device anywhere within a room, making dead batteries a thing of the past." says David Smith, professor at Duke University and one of the authors of the paper. The new system would stretch that range by making use of higher microwave frequencies, and focus the waves towards a device in a room by running them through a flat, LCD-like panel. In this case, each cell in that metamaterial could be tuned to manipulate the electromagnetic wave as desired, which can focus the beams of energy from a wall-mounted panel the size of a TV down to something as small as a smartphone, anywhere in the room.

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