MIT team lights it up -- without wires
The latest MIT news flash could finally allow consumers to cut their power cords: A Massachusetts Institute of Technology research team has figured out how to wirelessly illuminate an unplugged light bulb from seven feet away.
Within the next five years, MIT physicist Marin Soljacic foresees a day when people could forgo the tangle of wires that keeps laptop, iPod, and cellphone users on a short leash. Instead, they could use a carefully designed magnetic field to deliver power to devices over the air. "At this point, this is a proof of principle -- the main point of our research was to see if we could transfer energy wirelessly," said Soljacic, who was inspired by the annoying beeps his cellphone made in the middle of the night when he forgot to charge it. "It occurred to me that it would be so great if the thing took care of its own charging."
Details about WiTricity, or wireless electricity, were reported yesterday in Science Express, an online publication of the journal Science.
In the demonstration, Soljacic and his team generated a magnetic field on one copper coil. Seven feet away, a similar coil specially tuned to resonate with the field received enough power to light up a 60-watt bulb. Typically, a laptop requires about 30 to 40 watts, he said, and an iPod or cellphone might require a few watts.
Already, some products have been developed that allow consumers to wirelessly charge their devices over very short distances.
But if Soljacic's idea bears fruit, consumers could be truly unplugged -- their rechargers and bulky adapters replaced by a device that transmits power wirelessly. The Army Research Office, the National Science Foundation, and the Department of Energy funded his research.
Chris Reidy can be reached at reidy@globe.com and Carolyn Johnson at cjohnson@globe.com. 