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June 8, 2015

New Technology in the Works to Power Devices Via Wi-Fi

Image courtesy of (Stuart Miles) /

There will be no more power cords for your Smartphone, tablet or laptop if a group of researchers at the University of Washington have their way.

Wi-Fi may soon be the only thing you need to charge your electronic devices thanks to the university’s ‘power over Wi-Fi’ technology.

The technology enables devices to be recharged wirelessly, through the air from as much as 30 feet away.

“We have a huge Wi-Fi infrastructure already in place,” researcher Vamsi Talla told Popular Science. “If we can repurpose existing infrastructure for power delivery as well, then we can actually enable wireless power delivery in homes and offices.”

Researchers have used Power over Wi-Fi to charge a super capacitor connected to a small camera from 17 feet away. And while the technology is far from perfect so far, it is working: the super capacitor collected enough energy over Wi-Fi, enabling a camera to take one picture every 35 minutes. The technology also was able to charge a small fitness tracker to 41 percent of its battery power in two-and-a-half hours.

Power over Wi-Fi uses a harvester to snag radio frequency (RF) power and convert it into usable direct current (DC) power.

Routers, on their own, can only manage just so much power at any given time, however. To address that limitation, the researchers have fashioned software that makes routers send power signals when user traffic does not meet a certain minimum. This offers uninterrupted charging and connectivity.

“If we wanted to just blast as much power as we possibly can, that would kill your Wi-Fi, because you’d have power on the channel all the time,” researcher Bryce Kellogg told Wired.

“We optimized the router so that… Instead of having continuous power on one of your Wi-Fi channels, we split it among your three non-overlapping Wi-Fi channels. That allows us to deliver about the same amount of power without impacting any one channel very much.”

The researchers have founded a start-up to turn their technology into a saleable product.

“The work we’ve published, you could think of it as the first proof of concept,” Talla told Wired. “But it’s by no means the optimal solution. We’re actively working to make it better.”


Jennifer Cowan is the Managing Editor for SiteProNews.