‘PoWiFi’ Enables Wireless Charging and Internet Access

A prototype Wi-Fi router can be used to charge devices wirelessly. Engineers at Washington University in the USA developed the ‘PoWiFi’ routers and have installed them in six homes. They use a technology called ambient backscatter, enabling two battery-free devices, powered by RF signals, to communicate. The router then sends out radio waves, which are converted into DC voltage using a rectifier. A DC-DC converter is used to raise the voltage level, so users can access the internet and charge their devices at the same time. (I have my doubts about the level of power available and efficiency – Man. Ed.)