NIST's Seiler agrees that RF-to-DC power has potential for certain kinds of devices. "It's promising but is limited by range and the amount of power an RF wave can hold. But it could power many smaller devices," he says.

Glossary

Beam forming: The ability of a wireless communication device to adjust its antenna parameters and tailor its signal directly at the receiver for greater speed and reliability.

Electroencephalography (EEG): The monitoring of the electrical activity of the brain with several electrodes placed on the scalp.

Functional magnetic resonance imaging (fMRI): An offshoot of magnetic resonance imaging, this technology can pinpoint areas of the brain that are being used during an activity.