energy scavenging tech harnesses electromagnetic frequencies in the 100MHz - 15GHz range -- anything from your FM car radio to radar -- and converts it into a useable DC power source. So, it's free energy -- kind of. The cheap, self-powering paper or flexible polymer-based sensors are created using standard inkjet printers and Tentzeris' "unique in-house recipe" of circuit-building silver nanoparticles. Current testing hasn't yet yielded significant enough wattage to power your PS3 Slim, but it could soon via the help of supercapacitors and future solar cell integration. Imagine clothing embedded with health-monitoring biometric sensors, airport security run by something other than aloof TSA agents, or even spoilage-aware drink cartons -- milk that tells you when it's gone sour. The invisible radio band-charged possibilities are endless, but with storage still in the microwatt to one milliwatt range, it's more concept than solid vaporware reality.