Researchers at Duke University’s Pratt School of Engineering have designed a power-harvesting device with efficiency similar to modern solar panels. The device wirelessly converts the microwave signal to direct current voltage capable of recharging a cell phone battery or other small electronic device, according to Applied Physics Letters.
It operates on a similar principle to solar panels, which convert light energy into electrical current. But this versatile energy harvester could be tuned to harvest the signal from other energy sources, including satellite signals, sound signals or Wi-Fi signals, the researchers say. The key to the power harvester lies in its application of metamaterials, engineered structures that can capture various forms of wave energy and tune them for useful applications.
Undergraduate engineering student Allen Hawkes, working with graduate student Alexander Katko and lead investigator Steven Cummer, professor of electrical and computer engineering, designed an electrical circuit capable of harvesting microwaves. They used a series of five fiberglass and copper energy conductors wired together on a circuit board to convert microwaves into 7.3 volts of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5 volts of power.
With additional modifications, the researchers said 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.
Make sure you visit and click ‘Like’ on our Facebook page to receive even more news and updates from Alternative Energy Africa.