Handheld windmills serve as electric generators
$this->bbcode_second_pass_quote('', 'I')t’s not quite nanotechnology, but these inches-long windmills can generate small amounts of electric energy to power a variety of low-voltage applications. Since they’re made entirely of plastic, they cost just dollars to manufacture, offering potential for many uses including battery recharging, lighting in remote areas, and wireless sensors.
The scientists’ most promising design so far involves three 5-in. (13-cm.) fans mounted on a single shaft through an adjustable gear ratio. Attached to the shaft, a crank arm pulls a lever that is attached to two rows of nine bimorphs. The lever causes the bimorphs to vibrate, converting random wind flow into synchronous mechanical motion. The entire generator size, which is 3.5x4x5.5 in.3, is made of acrylonitrile butadiene styrene (ABS) plastic.
At an average wind speed of 10 mph, the windmill can generate 5 mW of continuous power at a rate of 12 volts. Although a fairly small amount of energy, the windmill can still power sensors, switches, alarms, and wirelessly transmit data, which would be especially useful in remote locations.


