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Field harvest.

I'm Bob Karson with the Discovery Files, from the National Science Foundation.

A team led by scientists from Penn State has developed a more effective way to get free energy. The electricity that (Sound effect: light switch) lights our homes and powers so much of our stuff creates low level magnetic fields -- all around us. Not to let a good energy source go to waste, the researchers found a way to harvest and convert magnetic field energy to electricity with 400 percent higher output than any process out there.

The device is about an inch-and-a-half long rectangle -- two paper-thin-layers. One end is clamped -- the other is open, free to vibrate. It combines two principles you may have forgotten from 8th grade Science: One material is magnetostrictive (mag net oh strick tiv) -- which converts a magnetic field into stress -- it vibrates. The other is piezoelectric (pee zo el ek trick), which converts vibrations into an electric field. Result: Magnetic field turned into electrical current. In tests, 4 inches from a space heater, the device powered 180 LED arrays.

(Sound effect: as Doc:) "And no, we're not talking jigawatts here Marty!" But, certainly enough power to run the wireless sensor networks needed to make buildings more energy efficient and reduce overall power consumption.

Harvesting energy from magnetism. What you might call a real 'power grab.'

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