"ENERGY: Vibrations good for harvesting electricity"

By converting vibrations into usable power, researchers are enabling the battery-free operation of ultra-low-power wireless devices for everything from medical implants to that black-box under the seat of new automobiles. If a sensor is needed but it is inconvenient to supply power--from the inside of a jet engine to the heart's aorta valve, for example--energy harvesters are being designed to convert environmental gradients into usable electrical power.
The latest batch of energy harvesters for vibrations use piezoelectric actuators sized to match the energy required by the application, from centimeter-sized fibers ruggedized to supply milliwatts in harsh environments, all the way down to micron-sized actuators fabricated using micro-electromechanical systems (MEMS) to supply microwatts to wireless sensors.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=200001350