MIT researchers explore method of transferring electricity wirelessly

November 19, 2006

Wednesday at the American Institute of Physics Industrial Physics Forum meeting in San Francisco, a group of researchers proposed new research into an old way, invented by Nikola Tesla, to transfer power wirelessly. Marin Soljacic and his MIT colleagues revived an idea which involves a source that creates a short range oscillating field. Nearby circuits that resonate at the frequency of the source absorb some of the energy. The system would operate in much the same way as the coils inside a transformer, except that the researchers believe they can develop sources that transfer energy over much longer distances than is typical in transformers. Technology based on this proposal could mean wireless gadgets such as cell phones and iPods never have to be plugged into a wall outlet. The researchers also propose that it could power micro-robots or other machines that are too small to carry their own batteries. Eventually it might enable electric transportation such as buses to recharge wirelessly through power sources near the roadway. One potential problem with the system could be its inefficiency. Soljacic's calculations show that it is at best 60% efficient.