The Secret Behind Geckos' Sticky Feet
If you've ever wondered how geckos can scale walls and hang from ceilings without falling, it turns out that toe hairs are the secret behind their remarkable climbing abilities, new research shows.
These little lizards can turn the "stickiness" of toe hairs on the bottom of their feet on and off, which enables them to run at great speeds and even cling to ceilings using little energy.
Gecko toes are well-studied and their sticky properties have inspired some incredible technology, such as stitch-free ways to seal wounds and hand-held paddles that may help US troops climb walls as a means for more safe and effective warfare.
However, it seems that nature is still outdoing technology.
"A gecko by definition is not sticky - he has to do something to make himself sticky," lead author Alex Greaney, a professor of engineering at the Oregon State University in Corvallis, told Live Science. "It's this incredible synergy of the flexibility, angle and extensibility of the hairs that makes it possible."
More specifically, it's the hundreds of tiny setae, or microscopic hairs, on their bulbous toes that make geckos expert climbers. Each seta splits off into hundreds of even smaller bristles called spatula, which, when they come in contact with a wall or ceiling, initiate van der Waals forces. Using a mathematical model, researchers found that the combination of these forces and the angle of its toe hairs contribute to the creature's sticky success, and enable it to scurry across surfaces at 20 body lengths per second.
Not to mention, this feature also requires little to no energy on the part of geckos.
"Absorbing energy makes for a tough adhesive joint - for the gecko, it means it can catch itself after jumping or falling and also enables a gecko to rapidly dart off in different directions to avoid predation," Greaney added in a statement.
Details of the research were published Aug. 12 in the Journal of Applied Physics.