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MIT creates MagMIMO: Wireless charging with the range of WiFi

A team at MIT has created a new wireless charging concept that will let you charge your phone over feet rather than centimetres.

Wireless charging is still a relatively new addition to the smartphone world, with a handful of devices like select Nokia Lumias, the latest Google Nexus devices and a smattering of LG, Motorola, HTC and other Android-based smartphones sporting the technology. Presently the most widely adopted standard is Qi, which is good for a distance of up to around a centimetre or so, but what about going truly wireless?

Qi wireless charger

The constraints of the current standards mean that all you’re really doing is plugging the cable you would put into the phone’s charging port into the wireless charger the phone has to sit on, no more than two-inches away; it’s technically wireless, but only marginally more convenient. A new technology being tested by a team at MIT currently offers a range of up to 30cms and could be stretched to work even further away.

If you own a fancy wireless router, there’s a good chance it uses MIMO technology to boost the signal when it detects that a particular device is in the vicinity and wants to connect. Using what’s called beamforming, the router can direct radio waves to ensure a better connection with your device; the MIT team’s concept modifies the same technology and swaps out radio waves for electromagnetic waves.

As Ryan Whitwam at ExtremeTech points out, focusing radio waves usually results in heat build up, a problem that doesn’t exist with electromagnetic beamforming. However in its place, directing concentrated electromagnetic waves could cause other electronic equipment caught in the crossfire to malfunction; a pacemaker for example.

The other limiting factor with wireless charging of any sort over conventional methods is speed. Based on current standards and battery technology a Qi 1.1 enabled smartphone will go from flat to fully charged in around 2 to 3 hours, the next iteration of Qi (version 1.2) promises charging from up to distances of 4.5cms and faster charging times.

MIT’s technology is notably slower and likely requires more energy to transmit those electromagnetic waves over a greater distance. Tested with an iPhone 4S, (which packs a relatively small 1420mAh battery) MagMIMO took around five hours to fully charge the device.

It’s early days, but such technology could prove immensely useful. You could charge you phone by placing it anywhere on your desk, or leaving it in your pocket. The technology could be embedded in the walls of your house, or at a bus stop.

They’ve still got a long way to go, but new wireless charging technologies like MagMIMO could change the way we use our smartphones out and about, unconstrained by the wall plug and free from the battery pack. In my opinion, that future can’t come soon enough.



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