Wi-Fi signals used to power surveillance camera
A regular Wi-Fi router has been tweaked by researchers in the US to make it capable of powering a battery-free surveillance camera continuously. What was even better was the fact that the routers data transfer speeds were not affected.
[Image Courtesy of LaughingSquid]
These news may help researchers to bypass one of the biggest challenges in developing new technology. This includes the Internet of Things, a project aiming to put a chip in appliances in homes to bring them online. It could mean that things could be powered without having to resort to the use of a lot of cords thanks to the appliances having to be plugged in.
Researchers have always known that Wi-Fi routers send out electromagnetic waves and that this could be harnessed for energy along with sending information out. However the main challenge that researchers had was to find a way to do it that was not only reliable but also continuous. Researchers at the University of Washington in the US have found a way to change the way that a router broadcasts and they have named their finding, PoWi-Fi, power over Wi-Fi.
Scientists have never been able to garner enough signals from Wi-Fi to be able to use it to power anything of use. The breakthrough of the scientists came after they attached an antenna to a temperature sensor so that they could check how much power they were able to collect from a nearby router. The results showed them that the signals from the Wi-Fi were not high enough to go over an operating threshold of about 300 minivolts, however they did come close.
The issue with Wi-Fi routers was that they don’t blast out electromagnetic waves continuously but rather send them in bursts in a single channel. When they programmed the router to broadcast noise over a range of channels when it wasn’t transmitting information, they could pump signals enough so that their antenna could be used and this provided power that was continuous to electronic devices.
The researchers used their prototype to show that they were able to run battery-free temperature and camera sensors via Wi-Fi signals from five and six metres. At the same time they showed that they were able to charge ranges of coin-cell batteries at up to as much as nine meters.
They used their prototype in six homes to prove that their set-up would work in a real life environment and to prove that it would not interfere with data transfer speeds. One question that remains unanswered is how the routers interfere with other signals in the region. Even if a problem does occur it could be solved in future generations. The researchers are now working on testing the routers in different conditions so as to make sure that they are able to offer power regularly for devices while using them to browse the internet. If so, then it could change the way that homes are powered.