Gear mechanism revolutionized the world and is now used everywhere from watches to airplanes. But, nature seems to have found out the efficiency of cogs and wheels much before man. A new study from University of Cambridge shows how a common insect uses mechanical gears in its hind legs to jump.
The amazing mechanism was found in juvenile Issus- which is found across Europe. This insect has hind-leg joints with strips of intermeshing teeth that are similar to cogs. These strips rotate to synchronize the insects' legs and help it jump efficiently.
Young Issus insects (Issus coleoptratus) are known to jump to about three feet in a single leap. During the jump, their hind legs move within 30 microseconds of each other, with a microsecond being a millionth of a second.
According to researchers this is the first observation of mechanical gearing in a biological structure. The study team used high-speed video camera along with anatomical analysis to understand how the insect makes use of these gears to jump.
Researchers found that the mechanical gear in insects was similar to the gears found in bicycle and car gear-box. They found that each gear tooth had a round corner at the point where it connects with the gear strips. The gear teeth on the opposing leg lock together, proving incredible synchronicity, according to a news release.
"This precise synchronisation would be impossible to achieve through a nervous system, as neural impulses would take far too long for the extraordinarily tight coordination required," said lead author Professor Malcolm Burrows, from Cambridge's Department of Zoology. "By developing mechanical gears, the Issus can just send nerve signals to its muscles to produce roughly the same amount of force - then if one leg starts to propel the jump the gears will interlock, creating absolute synchronicity."
The asymmetrical gears help the insects power their jump forward. In machines, symmetrical gears are used as they need to be rotated in both directions.
The structures in the hind legs were actually discovered way back in 1957, but no one was able to demonstrate how they function, Burrows told LiveScience.
"We usually think of gears as something that we see in human designed machinery, but we've found that that is only because we didn't look hard enough," added Gregory Sutton, now at the University of Bristol , co-author of the study. "These gears are not designed; they are evolved - representing high speed and precision machinery evolved for synchronisation in the animal world."
The study is published in the journal Science.
University of Cambridge has earlier studied fleas' ability to jump. Check this site for more information.