KSC Biomimicry - Gecko Adhesion: The Pulse of the Planet daily radio program offers free legal online mp3 downloads, exploring the world of sound in nature, culture and science, with audio adventures, world music, extraordinary sound portraits, science diaries, and nature ring-tones; an amazing sonic experience.

Airdate: Oct 13, 2009
Scientist: Dr. Ron Fearing

KSC Biomimicry - Gecko Adhesion

KSC Biomimicry - Gecko Adhesion
Gecko feet aren't sticky, but they adhere to almost any surface.

music; ambience

RF: “So one of the really fascinating things we’ve found in the last few years is how do geckos stick to walls; the fundamental reason behind this turns out to be a universal thing.”

It’s the sort of thing that could lead to a new kind of superhero. I’m Jim Metzner, and this is the Pulse of the Planet. UC Berkeley engineer Ron Fearing develops materials with special characteristics, and he does this by paying close attention to the natural world. Well, it turns out that geckos have the unique ability to climb walls, not by having sticky stuff on their feet, but by utilizing a natural principle of attraction that’s only recently been recognized by scientists. Ron Fearing explains.

RF: “When you bring two very small things in contact, they’re attracted to each other. Basically, there’s instantaneous motion of the electrons and the atoms, and they cause two things to be attracted to each other. If you stick your finger on a desk, unless there’s something sticky on there, you don’t really notice that you’re being attracted to the table. Well, that’s because you can’t sense it. It’s such a small force.”

Now, multiply that force by millions, and you could climb a wall like Spiderman. Or Gecko-man.

RF: “The secret behind the gecko adhesion is that rather than making just a single contact with a few nanonewtons of force, they have millions or hundreds of millions of contacts simultaneously. So, if you looked at detail at the end of a gecko toe, there would be tens of thousands of fibers on that toe, and on each fiber there would be up to a thousand nanofibers on the end of that fiber. And you can imagine millions of these contacts. And each one of these contacts makes a very small amount of adhesive force, but you have so many of them that they combine together; you get real significant forces you can really feel.”

Ron Fearing is one of the scientists participating in the Kids’ Science Challenge, our nationwide competition for third to sixth graders, made possible by the National Science Foundation. You’ve been listening to Pulse of the Planet. I’m Jim Metzner.