Lot’s of people have an interest in harvesting RF energy as a “free” source of power. It’s important though to understand the applications that have a good fit and those that don’t.
At the 2010 CES, an RCA-branded device called the Airnergy WiFi Energy Harvester was demonstrated. The device has an RF energy harvester and an internal battery. It was claimed that the device recharged most of a BlackBerry battery in 90 minutes. We can only conclude that was from the internal battery and not from a WiFi router (a typical WiFi router puts out only 100mW). We’ve posted below the CES video and an entertaining analysis of this device by David Jones of the Electronics Engineering Video Blog.
Dave Jones - EEV Blog
RCA Airnergy video from 2010 CES