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  • Counter :
  • 760
  • Date :
  • 6/9/2007

Wireless Energy Transfer Possible

an abstract picture

US researchers have developed a wireless energy transfer technology that could charge a computer or cell-phone battery from across a room.

Massachusetts Institute of Technology scientists said their innovation may soon eliminate wires that tether our machines to wall sockets, or may keep batteries topped up and ready to go.

They made a 60-watt light bulb glow by sending it energy wirelessly -- from a device two meters (7 feet) away.

The fledgling "WiTricity" technology is potentially heralding a future in which cell phones and other gadgets get juice without having to be plugged in.

Six MIT researchers worked four years on the problem.

The technology has already piqued the interest of some big names in consumer electronics.

Venture capitalists have been lining up with offers for the researchers who are now figuring how to turn their pet project into a marketable commodity.

Aristeidis Karalis, a member of the team Said, "This invention could free us from power cables and ideally replace batteries to a good extent, at least in the context of a home or office setting."

Marin Soljacic, a professor of physics at MIT in Cambridge, Massachusetts who led the six-person research team explained the technology is simple.

It is based on resonance, which causes an object to vibrate when energy of a certain frequency is applied to it, he said.

Two resonant objects on the same resonance frequency can exchange energy efficiently, while interacting weakly with objects that are not on the same wavelength.

For the light bulb experiment, the MIT team used electromagnetic resonators in the form of copper coils.

One of the coils was attached to a power source. The other acted as a receiver.

The transmitter emitted electrical vibrations of a certain frequency which rippled across an electromagnetic field to the receiver or "resonator" two meters (seven feet) away.

In this experiment, the system was operating at 45 percent efficiency, but investigators hope to raise that to the 70-80 percent level by using different materials and tweaking the technology.

However, they are confident they can enhance the system and make it reliable enough so that consumers can dispense with power cords and even batteries for their laptops, PDAs, Blackberries or cellphones if they are being used in the same room as the power source.


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