Wireless power

You won't have to plug in your TV, and your iPhone will charge in your pocket.
For all of the progress we’ve made in developing wireless phones and Internet, we still depend on wires for one thing: when our devices run out of juice, we have to plug them into the wall. The more devices, the more tangled that mess of wires becomes. But Massachusetts-based WiTricity is working to free humanity from the tyranny of cords.
The company is developing a device that can be placed in the ceiling or on the wall of a room and wirelessly power just about anything that depends on electricity, ranging from lights to televisions to laptops. The prototype device can even recharge a cellphone while it’s in your pocket.
WiTricity, a spinoff from the Massachusetts Institute of Technology, was co-founded by physics professor Marin Soljacic in 2007. He began investigating wireless electricity transmission after being awakened one too many times by his wife’s phone, which began beeping whenever it needed to be recharged. Soljacic looked to the principle of magnetic induction for the answer. The trick was to run a current through electromagnetic coil, which converts the energy into a magnetic field. That field, in turn, could induce small coils embedded in wireless devices to generate electricity. WiTricity has improved the technique to allow for transfer over longer distances, meaning you could have a central coil in your ceiling powering all your devices, with secondary coils in your electronics to receive the power. The problem was the massive amount of power that can be lost through the process, but WiTricity claims to have invented technology that permits 90% efficiency in some cases, compared to using a cord.
WiTricity is now trying to convince manufacturers to include induction coils in their devices so they can be charged wirelessly. The company says that some such devices could be released by the end of this year. For now, the chargers will work at a distance of only up to one metre, but over the next five years, WiTricity hopes to sell chargers that will work over greater distances, and eventually produce systems able to silently power multiple devices wherever they are located in a room. “People take wireless communications for granted,” says David Schatz, the company’s director of business development. “The same thing will happen with charging. It will become an afterthought.”
WiTricity has competition, however. Devices are already hitting the market that employ magnetic induction over shorter distances. Powermat USA and Fulton Innovation, both firms in Michigan, sell pads that recharge phones and other gadgets that are placed directly on top. But they also are struggling with the fact that few phones and laptops come with induction coils built in. For now, an iPhone, for example, needs to be slipped into a special case (purchased separately) that contains the secondary coil required to recharge the battery. “One of our primary goals is getting into devices,” says Dave Baarman, Fulton’s director of advanced technologies. His company has already collaborated with Dell to release the Latitude Z last year, a laptop that can be powered wirelessly — assuming you’re willing to shell out US$349 for the wireless charging stand.
But while the technology for wireless charging is largely ready, a brewing standards war may slow its release. An iPhone in a Powermat case can’t be recharged on a Fulton pad, for example. To solve this problem, the Wireless Power Consortium — which counts Fulton as a member, along with Research in Motion and Nokia — is developing compatibility standards for wireless electricity.
The group is also working hard to make sure there are plenty of convenient places to charge devices in the future. Baarman says furniture makers are interested in creating tables and desks with built-in charging pads. Car companies are also looking into built-in charging pads, allowing you to power up on your way to work.
All of this suggests that one day soon, adaptors will be a thing of the past. “I picture in a couple of years being able to walk into a coffee shop, set down my phone, and leave with it being fully charged,” says Vlad Grodzinskiy, assistant product manager at Powermat. Considering how quickly wireless communication became the norm, cutting that final cord can’t be far behind.