What if you could generate energy simply by walking? Or by boogie-ing on a dance floor? Or by driving your car on any old road?
That's the premise behind piezoelectricity. Certain crystals or ceramic materials can generate an electric charge simply by having stress applied to them — the stress, for example, of a person walking on or a car driving over them.
A dance club [1] in Rotterdam, Netherlands, has already embedded the technology in its dance floor, and the energy harvested from patrons' moving and grooving powers club light displays — accounting for 10 percent of the establishment's electricity.
The best way to harness piezoelectricity on a large scale continues to elude scientists, but some research under ways includes:
- A Japanese railway company [2] is currently testing a piezoelectric floor under its ticket gates. If successful, the floor could be used to power the gates themselves, as well as electronic displays.
- An Israeli company [3] is planning to test piezoelectric generators on a 100-meter stretch of roadway. They hope their system will eventually be able to produce 100 KW per kilometer stretch of two-way road and, if successful, could be applied to railroad tracks and airport runways as well.
- The Pentagon has explored using the technology to harvest energy from soldiers' boots [4], which could reduce the amount of batteries troops have to carry to power gear like nightvision goggles and communication devices. Unfortunately, researchers have found that the technology takes its toll on the troops — some soldiers have complained that a day in piezoelectric boots is like spending a day walking through quicksand.
- A Texas professor is even looking into harnessing the technology to create a self-powered cell phone [5], on the principle that sound waves could apply enough stress to nano-sized piezoelectric materials inside the phone to generate the energy it needs to function.
I certainly hope they figure out how to do this, though. I know some bouncing-off-the-wall four year-olds I wouldn't mind putting to work generating energy for the rest of us.
Photo courtesy of WATT [6].