Small Power Generators

New Generator Produces AC Current by Stretching Zinc Oxide Wires is the title of a news release of Georgia Institute of Technology. The article discusses tiny electric power generators producing alternating currents by taking advantage of piezoelectric properties of zinc oxide structures. The idea is to convert mechanical energy into electrical energy. Researchers anticipate that small generators will power devicess used by medical sensors as well as areas like defense technology and consumer products. The local environment would supply power needs, eliminating the necessity of an external power source. This quote does much to explain:

To boost the current produced, arrays of the flexible charge pumps could be constructed and connected in series. Multiple layers of the generators could also be built up, forming modules that could then be embedded into clothing, flags, building decorations, shoes – or even implanted in the body to power blood pressure or other sensors.

When the modules are mechanically stretched and then released, because of the piezoelectric properties, the zinc oxide material generates a piezoelectric potential that alternately builds up and then is released. A Schottky barrier controls the alternating flow of electrons, and the piezoelectric potential is the driving force of the charge pump.

“The electrons flow in and out, just like AC current,” Wang explained. “The alternating flow of electrons is the power output process.”