Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Wireless Recharging

MIT Researchers send power two meters with no wires.

Using a simple setup–basically, two metal coils–MIT researchers have demonstrated for the first time that it’s feasible to send power wirelessly as far as two meters. The approach might someday make it possible to charge batteries in laptops, cameras, or phones without plugging them in, says MIT physicist Marin ­Soljaˇci´c, who led the research with physicist John Joannopoulos. The technique involved, magnetic inductive coupling, has long been used to transfer power between transformers a few centimeters apart, but the MIT group extended its range by focusing the energy at a specific frequency. Power in a cable (1) is transferred to a copper coil antenna (2) that includes a disclike capacitor (3). The coil produces a magnetic field of around 10 megahertz. Energy (4) is transmitted by the magnetic field and received by an antenna (5) also resonating at around 10 megahertz. Ultimately, such a receiving antenna could be built into consumer electronics.

Credit: John Macneill

Couldn't make it to EmTech Next to meet experts in AI, Robotics and the Economy?

Go behind the scenes and check out our video
Want more award-winning journalism? Subscribe to Insider Basic.
  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning print magazine, unlimited online access plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Print Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.