If you have ever wondered how geckos manage without any effort to run up and down the walls as if these are just horizontal surfaces on the ground, a new study conducted by researchers from the Oregon State University could just give you an idea how this nocturnal animal could cling to vertical and upside-down horizontal surfaces, a feat that humans can't normally do.
It appears that the lizard's little secret that gives it the special ability to stick to any surface has something to do with the tiny hairs that can be found at the bottom of their feet. Geckos can apparently turn the stickiness of their toe hairs, otherwise known as "seta," on and off without spending much energy and this bizarre but special ability allows these animals to be very good at either clinging to any surface including ceilings and walls as if defying gravity or running at great speeds.
For the new study published in the Journal of Applied Physics on Aug. 12, Alex Greaney, an assistant professor of mechanical engineering at the Oregon State University, and colleagues developed a mathematical model that unveiled the mechanism that allows the lizard to switch the stickiness of their feet on and off.
Greaney said that the feet of the lizards are not sticky by default and the stickiness can only be activated with the application of a small force. He said that all it takes is a small angled force to put the seta into the sticky position and these tiny hairs will unstick seamlessly in the absence of this force, which explains why the seta can support 50 times the weight of the gecko while it sticks from the ceiling but do not get in the way when the lizard runs at a speed of 20 body-lengths per second to escape its predators.
"These are really fascinating nanoscale systems and forces at work. It's based not just on the nature of the seta but the canted angles and flexibility they have, and ability to work under a wide range of loading conditions," Greaney said.
Researchers look forward to learning more about the adhesion system of geckos as applying this mechanism could potentially lead to practical uses such as in the development of better adhesives as well in improving the performances of robots.
