Wi-Fi Power Transmission Technology

University of Washington engineers have developed a technology that allows you to use Wi-Fi as an energy source to power portable devices and charge gadgets. The technology has already been recognized by Popular Science magazine as one of the best innovations of 2015.

The ubiquity of wireless data technology has revolutionized itself, and now it's the turn wireless energy transmission by air, which developers from the University of Washington called PoWiFi (from Power Over WiFi).

At the testing stage, the researchers were able to successfully charge small-capacity lithium-ion and nickel-metal hydride batteries using the Asus RT-AC68U router and several sensors located at a distance of 8.5 meters from it. These sensors just convert the energy of the electromagnetic wave into direct current with a voltage of 1.8 to 2.4 volts, which are needed to power the microcontrollers and sensor systems.

The peculiarity of the technology is that the quality of the working signal does not deteriorate, it’s enough just to reflash the router, and you can use it as usual, plus supply power to low-power devices.

At one of the demonstrations, a small low-resolution covert surveillance camera was successfully powered, located at a distance of more than 5 meters from the router. Then, the Jawbone Up24 fitness tracker was charged at 41%, it took 2.5 hours.

When asked why these processes do not negatively affect the quality of the network communication channel, the developers answered that this is possible due to the fact that the flashed router, during its work, sends energy packets to the channels that are not transmitting information.

They came to this decision when they discovered that during periods of silence energy simply flows out of the system, and yet it can be used to power low-power devices.

In the future, PoWiFi technology could well serve to power sensors built into household appliances such as coffee makers, air conditioners, and washing machines to control them wirelessly.

Such sensors are already very common, they do not require much energy, but serve only for control, so over time the need for their connection to traditional power sources will disappear. Who knows, maybe it will come to charging cell phones and other mobile devices, engineers do not exclude this possibility.

During the research, the PoWiFi system was placed in six houses, and offered residents to use the Internet as usual, download web pages, watch streaming video, and then tell what changed.

As a result, it turned out that the network performance did not change in any way, that is, the Internet worked as usual, and the presence of the added option was not noticeable. And these were just the first tests when Wi-Fi collected relatively small amounts of energy.

The developers' plans, however, are to improve the PoWiFi system, increase its efficiency using numerous sensors over long distances, and thus scale it. Already in December 2015, at the conference CoNEXT 2015 in Heidelberg, Germany, the Association for Computer Engineering presented the final document on PoWiFi.