Harvest Energy

source: popsci.com

Device Could Harvest Wasted Energy From Wi-Fi, Satellite Signals

It converts stray microwaves into electricity. 

By Shaunacy Ferro

Power Up 

Duke University

A wireless device developed by researchers at Duke University that converts microwaves into electricity could eventually harvest Wi-Fi or satellite signals for power, according to its creators. It could also one day be built into cell phones to let them charge while not in use, they say.

Its energy-harvesting capabilities come courtesy of a metamaterial, a synthetic material engineered with characteristics not found in nature, like the ability to bend light the wrong way or shrink when you stretch it. In this case, the microwave-harvesting metamaterial that acts kind of like a solar panel, converting microwaves into up to 7.3 volts of electricity, enough to charge small electronics. It can scavenge stray signals, like from appliances or satellites, to improve efficiency and make lost energy usable.

“It’s possible to use this design for a lot of different frequencies and types of energy, including vibration and sound energy harvesting,” according to Duke graduate student Alexander Katko, one of the inventors.“Until now, a lot of work with metamaterials has been theoretical."

The device is described in the journal Applied Physics Letters.