Researchers demo power over wireless technology

Massachusetts Institute of Technology researchers made a 60-watt light bulb glow by sending it energy wirelessly, from a device 7 feet away, potentially heralding a future in which mobile phones and other gadgets get juice without having to be plugged in, an Associated Press report said.

The Associated Press report said the  breakthrough, disclosed in Science Express, the online publication of the journal Science, is being called 'WiTricity' by the scientists.

The concept of sending power wirelessly isn't new, but its wide-scale use has been dismissed as inefficient because electromagnetic energy generated by the charging device would radiate in all directions, the report said.

One advance was announced last fall, when MIT physics professor Marin Soljacic said he had figured out how to use specially tuned waves, according t the report.

The key is to get the recharging device and the gadget that needs power to resonate at the same frequency, allowing them to efficiently exchange energy, the rpeort said.

The truly new step, was that the MIT team carried the concept out, as the scientists were able to light up a 60-watt bulb that had 'no physical connection' with the power-generating appliance, the report said.

However, the technology has a long ways to go before it becomes practical.

The MIT system is about 40% to 45% efficient, meaning that most of the energy from the charging device doesn't make it to the light bulb, the report further said.