Yes you read it right. Students of Duke University came up with a ground breaking way to charge mobile phone or any other devices by harvesting energy from wireless Internet waves.
Allen Hawkes and Alexander Katko of Duke University’s Pratt School of Engineering are a couple of smart guys who developed an innovative way to produce electricity with similar efficiency as solar panels, by harvesting microwave signals from the air.
Great thing about this device is, it can be tuned to gather the signals from whole bunch of energy sources, like satellite and sound signals or Wi-Fi signals. The main reason behind such capabilities can be found in application of metamaterials - engineered structures that are able to capture various forms of wave energy and turn them or better tune them for useful utilizations.
Katko and Hawkes used a series of five fiberglass and cooper energy conductors, which they wired together on a circuit board. The setup can convert microwaves into 7.3V (Volts) of electricity. To compare it to USB charges for your mobile phone, which provide around 5V of output.
Their next challenge is to boost up the energy efficiency from 6 to 10 percent to dramatic 37 percent, comparable to efficiency you get in solar cells.