Saturday, October 13, 2007
Biomimetics Update: Would tree frogs stick to horse hooves?
Biomimetics is in the news again. The word that is kind of fun to say means "taking design ideas from nature" or mimicking things that we see work well in the natural world.
The latest hotspot in the product design world is the foot of high-climbing tree frogs, or geckos and other lizards that seems to defy gravity. If you've ever spent a lazy siesta in Mexico watching the lizards scale sun-scorched walls, you too may have marveled, "how the heck can they do that?"
A scientist named Jon Barnes at the University of Glasgow in Scotland has made a career out of studying tiny tree frogs and how they move about. Tree frogs and cricket toes contain microscopic channel patterns that prevent cracking. If an adhesive could avoid cracking, it would be reuseable.
Scientists at the Indian Institute of Technology have cracked the code and a new generation of adhesives called "Geckel Glue" will be announced in tomorrow's issue of the journal Science. The glue is made of gecko hairs and mussel protein fibers.
Researchers found they could increase the adhesive strength by partially filling the microchannels with fluid. The surface tension of the liquid creates a capillary effect—the ability of one substance to draw another toward it like a sponge soaking up water.
Geckos have hair? Apparently, yes, there are microscopic, spatula-tipped hairs on gecko feet. And you don't have to convince me that mussels have something special going on; no matter how hard the waves crash on the rocks around here, the mussels never budge.
And best of all, mussels cling even when submerged, and the new Geckel glue is supposed to excel in moist environments.
A new design of tire tread that biomimics tree frog feet is also in development. Maybe some plastic shoe designer is reading this...tree frog toe pads might come in handy when a horse has to climb a trail like in the Tevis Cup endurance ride in California.
Maybe Geckel Glue will even hold a shoe on...or at least put the cup holder in my car back together...but can anyone tell me the biomimetic origin of "Gorilla" Glue?
Photo links to National Geographic article on gecko and mussel adhesion.