MIT researchers have worked out a theoretical scheme for a wireless-energy transfer that could charge or power devices within a couple of meters of a small power “base station” plugged into an electrical outlet.

The power base station would emit low-frequency electromagnetic radiation in the range of 4 to 10 megahertz. A receiver within a gadget–such as a power-harvesting circuit–could be designed to resonate at the same frequency emitted by the power station. Within a couple of meters of the station, it would absorb the near-field energy.