This Wi-Fi router powers sensors in a low-resolution camera, as well as several other devices. (Image courtesy of Dennis Wise and the University of Washington.)

Since the turn of the last century, engineers and scientists have worked toward Nikola Tesla’s dream of wirelessly powering the world.

Now, a method for turning Wi-Fi routers into wireless power stations may help to realize that dream.

Sending Power Packets over Wi-Fi

The peak energy contained in untapped, ambient Wi-Fi signals often comes close to meeting the operating requirements for some low-power devices.

However, since most Wi-Fi signals are sent intermittently energy tends to “leak” out of the system during silent periods.

Researchers at the University of Washington report that they have developed a solution to this Power Over Wi-Fi (PoWi-Fi) problem.

The team optimized a router to send superfluous “power packets” over Wi-Fi channels not currently in use. This allows power transmission over the Wi-Fi signal without affecting the quality and speed of data transmission.

In addition to modifying the router, the research team developed sensors that can be integrated into devices to harvest the wireless power.

Wireless Power in the Home

In their proof-of-concept experiments, the researchers demonstrated that PoWi-Fi could power an Omnivision VGA camera from 17 feet away.

Though the low-power camera could only take pictures in grayscale, it received enough power to capture an image every 35 minutes.

In another test, the router recharged a Jawbone YP24 wearable fitness tracker from 0 percent to 41 percent in two and a half hours.

The most encouraging results came from tests in six homes. Residents using the modified routers reported no noticeable deterioration in webpage loading or video streaming.

According to the researchers, this indicates that PoWi-Fi technology can deliver operational power to wireless devices without degrading overall network performance.

Wireless Power for Everyone?

The research team believes that PoWi-Fi technology could help to encourage IoT development. One of the major challenges for the Internet of Things is energizing the low-power sensors and actuators that connect smart objects without having to plug them in.

PoWi-fi offers a simple solution to this IoT power problem by using our existing wireless infrastructure to charge IoT devices. Theoretically, this should reduce the cost of IoT development.

"In the future, PoWi-Fi could leverage technology power scaling to further improve the efficiency of the system, to enable operation at larger distances and to power numerous more sensors and applications," said Shyam Gollakota, assistant professor of computer science and engineering at the University of Washington.

If PoWi-Fi really can operate at longer distances and power more devices, Tesla’s dream may become a reality.

For more information, view the paper online.