This isn't new. A "crysal" radio works the same way. http://www.instructables.com/id/Build-an-antique-style-crystal-radio/ http://www.instructables.com/id/Buil

This isn't new. A "crysal" radio works the same way. http://www.instructables.com/id/Build-an-antique-style-crystal-radio/ http://www.instructables.com/id/Build-an-antique-style-cryst... You can use a Crystal radio to power an LED, or a lot of things, the stronger the RF source, the more power you can extract. The problem is they aren't efficient if you are using them as a power source. When you are pulling "free" energy out of the airwaves they are cool, all that wasted AM band, but if you are broadcasting just to power your cell phone they are about .1% efficient. That's not a very eco-friendly.