Using WiFi to Power Small Electronic Devices

Research into other ways to use WiFi.

Finding a connected ( and staying connected) has become almost a daily necessity and the world becomes more reliant of the internet and wireless devices to connect to. How many times have you had to search around for a good WiFi connection or try to find a free one when you are travelling away from your home? 

Now there is new research to use the power produced by WiFI that is not needed by a computer to power small electronic devices.

University of Washington engineers have developed a novel technology that uses a Wi-Fi router — a source of ubiquitous but untapped energy in indoor environments to power devices.

The Power Over Wi-Fi (PoWiFi) system is one of the most innovative and game-changing technologies of the year, according to Popular Science, which included it in the magazine’s annual “Best of What’s New” awards announced Wednesday.

The technology attracted attention earlier this year when researchers published an online paper showing how they harvested energy from Wi-Fi signals to power a simple temperature sensor, a low-resolution grayscale camera and a charger for a Jawbone activity tracking bracelet.

The final paper will be presented next month at the Association for Computing Machinery’s CoNEXT 2015 conference in Heidelberg, Germany, on emerging networking experiments and technologies.

“For the first time we’ve shown that you can use Wi-Fi devices to power the sensors in cameras and other devices,” said lead author Vamsi Talla, a UW electrical engineering doctoral student.

We also made a system that can co-exist as a Wi-Fi router and a power source and doesn’t degrade the quality of your Wi-Fi signals while it’s powering devices.

PoWiFi could help enable development of the Internet of Things, where small computing sensors are embedded in everyday objects like cell phones, coffee makers, washing machines, air conditioners, mobile devices, allowing those devices to “talk” to each other. But one major challenge is how to energize those low-power sensors and actuators without needing to plug them into a power source as they become smaller and more numerous.

The team of UW computer science and electrical engineers found that the peak energy contained in untapped, ambient Wi-Fi signals often came close to meeting the operating requirements for some low-power devices. But because the signals are sent intermittently, energy “leaked” out of the system during silent periods.

The team fixed that problem by optimizing a router to send out superfluous “power packets” on Wi-Fi channels not currently in use — essentially beefing up the Wi-Fi signal for power delivery without affecting the quality and speed of data transmission. The team also developed sensors that can be integrated in devices to harvest the power.

In their proof-of-concept experiments, the team demonstrated that the PoWiFi system could wirelessly power a grayscale, low-power Omnivision VGA camera from 17 feet away, allowing it to store enough energy to capture an image every 35 minutes.

It also re-charged the battery of a Jawbone Up24 wearable fitness tracker from zero to 41 percent in 2.5 hours.

The researchers also tested the PoWiFi system in six homes. Users typically didn’t notice deterioration in web page loading or video streaming experiences, showing the technology could successfully deliver power via Wi-Fi in real-world conditions without degrading network performance.

Although initial experiments harvested relatively small amounts of power, the UW team believes there’s opportunity for make the PoWiFi system more efficient and robust.

Co-author Shyam Gollakota, assistant professor of computer science and engineering commented:

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 power numerous more sensors and applications.

About the Research

The research is funded by the National Science Foundation, Qualcomm and the UW.

After Thoughts…..

I hope this wont mean that less of the power that is needed for the internet connection is available and that we may have an even harder time connecting. My other concern is that this may mean that we are going to increase the amount of wireless energy that is around us everyday. Do we really understand what this may mean for humans exposed to so much electromagnetic radiation?

CREDIT Dennis Wise/University of Washington

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