[djf]

????

I have an electric toothbrush that charges without wires, just set it on the base.

Put a pickup coil with a diode in it and set it on a wire running AC, and you'll charge.

How much schooling exactly does it take to call yourself an engineer these days?

[annie laurie]

Yes, but does your toothbrush charge while not touching the base? That's the key here :)

[right-wingin_It]

This inductive coupling stuff is ancient knowledge. I would eexpect they've been using it in recharging the batteries in peoples pacemakers etc.

[Myrddin]

I was thinking of the magnetically coupled electric toothbrush as I was reading the article. No real magic here. Trying to make an antenna to capture a strong RF field and rectifying it is a very inefficient means of coupling energy. The RFID devices have a fairly long antenna to drive a very low power chip. The coupling distance is 2 to 6 feet. It's not a very practical concept for recharging something like a cell phone.