That little lizard that has become so effective selling car insurance – the gecko – can climb across glass windows and across the ceiling. You knew that, right?
The science of that ability has intrigued researchers at Ohio’s University of Akron for several years because it has so much potential for application in such areas as construction materials and medicine.
They’re so intrigued, they’re asking tougher questions of the 50 little lizards kept in two labs at the Auburn Science Center.
“OK, buddy, how about this one: Can you walk on Teflon?”
The answer: not very well. The popular DuPont nonstick product not only resists cheese omelets, but it also presented a significant challenge to the hairy toes of the gecko.
Yes, hair. That’s the secret. Not glue or liquids or surface tension. They have hairy toes – much like bristles – with thousands of them in one square millimeter, tipped with something called a spatula, so tiny it is not much larger than the wavelength of visible light.
And what researchers have found is that the questions are endless, and students are a tremendous resource. Undergraduate student Nicholas Wucinich, for example, a biology major who will graduate this month, asked: What if the Teflon is underwater?
“I didn’t have an answer,” said Alyssa Y. Stark, a doctoral candidate in the integrated bioscience program. “I also didn’t think the results would be all that interesting. If they don’t stick in air, why should they stick in water?”
But Stark and her colleagues were in for a surprise. “They stuck,” she said.
Peter H. Niewiarowski, professor of biology and integrated bioscience and one of the principal investigators at the university’s Biomimicry Research and Innovation Center, likes to talk about the Tom Cruise character in the film “Mission Impossible: Ghost Protocol,” who, with gecko-like gloves, was able to climb the shiny surface of a skyscraper.
“Having the ability to climb like a gecko immediately captures the imagination of kids and adults alike,” he said. “Why is that scene so engaging? I suppose it is the degrees to which it seems so within our grasp. … Bugs and geckos can do it. How is it we can’t with all our engineering and technology prowess?”
While the movie trivializes the application, Niewiarowski said it helps translate to the public how important the practical uses of the gecko sticking mechanism could be.
There are revolutionary implications, he said. A material that has the sticking power of a gecko’s feet could lead to new construction materials, or to bandages for closing wounds and skin after surgery.
“We use fasteners that are hard to acquire or involve toxic byproducts that are hard to recycle,” Niewiarowski said. “What if you can fasten the corners of walls by using a gecko-inspired fastener? Then you could break down the walls and move them around and create a different living space.”
As they make new discoveries about the gecko, the possibilities for application expand.
“I think we really still don’t understand how geckos deal with wet environments and remain sticky,” he said.
Polymer science professor Ali Dhinojwala, one of the lead researchers who studies adhesion, said one of the most significant challenges is that synthetic sticky things don’t easily release, as does a gecko foot pad. For example, he said, duct tape stuck to itself is nearly impossible to pull apart. He also is fascinated with the fact that the gecko foot pads are self-cleaning, which means they can walk on a dirty surface. Using carbon nanotubes, or molecular cylindrical tubes, researchers have developed a “gecko tape” that is more sticky than the gecko’s feet.