An energy-harvesting device capable of utilizing the signals from a wide variety of energy sources — such as microwaves, Wi-Fi signals, satellite signals, and sound signals — has been created by researchers at Duke University’s Pratt School of Engineering.
While the concept itself isn’t anything new, the execution in this case is — the new device has achieved an energy conversion efficiency of up to 37%, putting it on par in that regard with solar cell technology,
Duke University provides some details:
They used a series of five fiberglass and copper energy conductors wired together on a circuit board to convert microwaves into 7.3V of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5V of power.
(With regard to potential uses) — a metamaterial coating could be applied to the ceiling of a room to redirect and recover a Wi-Fi signal that would otherwise be lost. Another application could be to improve the energy efficiency of appliances by wirelessly recovering power that is now lost during use. With additional modifications, the power-harvesting metamaterial could potentially be built into a cell phone, allowing the phone to recharge wirelessly while not in use. This feature could, in principle, allow people living in locations without ready access to a conventional power outlet to harvest energy from a nearby cell phone tower instead.
(Or) a series of power-harvesting blocks could be assembled to capture the signal from a known set of satellites passing overhead. The small amount of energy generated from these signals might power a sensor network in a remote location such as a mountaintop or desert, allowing data collection for a long-term study that takes infrequent measurements.
Read more at cleantechnica.com