Gadgets Powered Wirelessly at Home With a Simple Wi-Fi Router

by Chris Baraniuk,  New Scientist

Throw away those power cords and chargers. Signals from a Wi-Fi router providing wireless electricity could soon be used to power gadgets and charge phones.

Our homes are a tangled mess of wires and chargers. But that might be about to change. Work is under way to use the Wi-Fi signals that surround us to power our gadgets.

A multi-university team of researchers has developed a system that can power electrical devices with just a wireless router’s signal, even while it provides wireless Internet access to an area.

How was this possible? The energy of the radio waves the router sent out was converted into direct current voltage with a component called a rectifier, much as solar panels convert light energy into electrical energy. That voltage was then boosted to a useful level by a DC-DC converter (arxiv.org/abs/1505.06815).

The system powered temperature sensors and battery-less low-resolution cameras, and charged standard batteries.

Using a traditional Wi-Fi signal, devices can be powered when the Internet is being used; however, when not browsing, the signal goes quiet. The new software broadcasts meaningless data across several Wi-Fi channels when the Internet is not being used, and small devices could use this signal as part of an Internet of Things, according to University of Reading researcher Ben Potter.

The researchers tested the system in six households in which modified electrical devices were put in the homes along with a Wi-Fi router. Over 24 hours, the devices were powered only by the router’s signal converted to electricity via a rectifier, while also continuing to provide wireless Internet to the home.

There could be high demand for this type of technology for the many sensors that will fill the smart homes and cities of the future. For example, sensors powered by Wi-Fi could be used to monitor air quality or the status of systems across a city.  Read the article