Airdate: Oct 13, 2009
Scientist: Dr. Ron Fearing
KSC Biomimicry - Gecko Adhesion
Gecko feet aren't sticky, but they adhere to almost any surface.
RF: â€œSo one of the really fascinating things weâ€™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.â€
Itâ€™s the sort of thing that could lead to a new kind of superhero. Iâ€™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 thatâ€™s only recently been recognized by scientists. Ron Fearing explains.
RF: â€œWhen you bring two very small things in contact, theyâ€™re attracted to each other. Basically, thereâ€™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 thereâ€™s something sticky on there, you donâ€™t really notice that youâ€™re being attracted to the table. Well, thatâ€™s because you canâ€™t sense it. Itâ€™s such a small force.â€
Now, multiply that force by millions, and you could climb a wall like Spiderman. Or Gecko-man.
RF: â€œThe 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.â€
Ron Fearing is one of the scientists participating in the Kidsâ€™ Science Challenge, our nationwide competition for third to sixth graders, made possible by the National Science Foundation. Youâ€™ve been listening to Pulse of the Planet. Iâ€™m Jim Metzner.