Artificial Butterfly

chewan · Post time 30-6-2010 08:42 PM

ciptaan yg teliti dan mengagumkan

chewan · Post time 30-6-2010 08:44 PM

Info kajian

The tiny machine flaps a pair of wings made of thin polymer film andcan stay airborne for four or five meters at a time, until the coiledrubber band powering it unwinds, Hiroto Tanaka of Harvard Universityand Isao Shimoyama of the University of Tokyo report in the June Bioinspiration & Biomimetics.

Theteam designed a model swallowtail butterfly and analyzed its flightpatterns as a way to investigate basic questions about flight that theycouldn’t study in live butterflies. “We can't ask insects, like ‘Hey,please just flap your wings at 10 hertz,’” Tanaka says.

Onequestion the researchers asked was whether simply flapping big wings upand down could reproduce a swallowtail’s undulating flight patternwithout the butterfly tweaking wing angles.

Swallowtails, likeother butterflies, have two wings on each side of the body, but theforewings overlap with the hind ones. That overlap might force thebutterflies to flap the hind and fore pair like one big wing, theresearchers speculated. Such overlaps are common among butterflies butnot among other four-winged flying insects, Tanaka says.
To mimicthe way the butterflies might use their front and rear wings together,the researchers created one big wing for each side of the body. Theyused a silicon-etching technique to make a mold for creating realisticwing veins and made a balsa wood “body” to keep the model’s weight at0.4 grams, near that of a real swallowtail.

With high-speedcameras, the researchers got enough images of the model’s few secondsof flight for motion analysis. They conclude that by simply flappingits wings straight up and down, the machine recreated the bobbingflight of real butterflies. And by comparing fully veined with veinlesswings, the researchers found that veins stiffened the wings and helpedthem achieve greater lift. The bobbing motion of the body alsoincreased lift to help keep the flier aloft.

The team’s analysisfits into the basic framework of what’s known about flight, says JaneWang of Cornell University, who also studies insect aerodynamics. “Thebasic picture that an up-and-down motion generates a forward thrust,thus forward flight, is known in classical aerodynamics going back to1930s, if not earlier,” she says.

sumber : sciencenews.org

dauswq · Post time 1-7-2010 01:59 AM

ith high-speedcameras, the researchers got enough images of the model’s few secondsof flight for motion analysis. They conclude that by simply flapping its wings straight up and down, the machine recreated the bobbingflight of real butterflies. And by comparing fully veined with vein less wings, the researchers found that veins stiffened the wings and helpedthem achieve greater lift. The bobbing motion of the body alsoincreased lift to help keep the flier aloft.

inilah kegunaannya