Battery recharges itself

Battery recharges itself
Inexpensive chips that could harvest mechanical energy to provide electricity in future wireless sensors.
Microgen Systems, a startup based in Ithaca in upstate New York, is working on new chips that can generate electricity from mechanical energy. The idea: The technology will be installed along with smaller batteries in low-cost wireless sensors that measure for example the tire pressure in your car or monitor environmental conditions in buildings over the years. This kind of self-sufficiency could be the sensors work independently, without having to be replaced with much effort batteries.
The core of the Microgen chip consists of a one square centimeter array, on which there are tiny silicon cantilevers. This freely oscillate when the chip is moved. At the base of the movable silicon levers are small pieces of a piezoelectric material. This is under stress, it produces electricity. The array is in turn mounted on a postage stamp-sized thin-film battery that stores the energy generated. Between piezoelectric material and turn an electric battery converter provides the necessary compatibility. The chip is moved, for example by a spinning car wheel, can be at least approximately 200 micro-watt power supply.
"If a suitable miniaturization 200 microwatts can be potentially very useful," David Culler of the Institute for Computer Sciences said at the University of California at Berkeley, who is considered a pioneer in wireless sensor networks for environmental monitoring and other autonomous applications.
However, Microgen is by no means the only company in this market. "Researchers develop energy harvesting using countless such systems, the light, heat, radio waves or vibrations, and then make available directly or stored in a battery." It adds that the traditional solar technology must first be defeated.
Robert Andosca, founder and president of Microgen system, said the specific nature of its action lies in the use of a self-developed piezoelectric material, which is also nontoxic. The commonly used variant in such elements, the PZT contains, however, lead.
When you think Microgen also a very cost-effective production. Competing devices are relatively large and often must be assembled by hand, which could cost hundreds of dollars in manufacturing. Since the Microgen micro-array systems (MEMS)-based, consisting of silicon, they are small and produced on standard equipment that is already used for computer chips. In mass production, such a device would cost only a dollar.
Microgen is a spin-off of the University of Vermont. The currently used experimental foundry to produce the first prototype is available at Cornell University. There were already various patterns of large semiconductor producers sent. Next time is now to manufacture in a commercial production line for MEMS will be hired to evaluate the mass production. Could be the first time then sold the chips in about a year.
The first market, thinking of the Andosca are tire pressure monitors. These sensors are in the United States are now legally required for new cars, because the correct tire pressure saves gas and contributes to driving safety. "This is to replace batteries is an extremely complicated process," says the founder of Microgen. The current generation of such measurement sensors can remain three years in the tires before they need to be replaced - every year 64 million of these batteries are installed. The Microgen-chip, however, would work best if an entire lifetime of the car.