Scientists prove how geckos stick, unlock secrets to making artificial ...( PORTLAND Ore.-- Geckos nature's supre...)

Now a team of biologists and engineers has cracked the molecular secrets of the gecko's unsurpassed sticking power--opening the door for engineers to fabricate prototypes of synthetic gecko adhesive.

"Two millennia later, we have solved the puzzle of how geckos use millions of tiny foot hairs to adhere to even molecularly smooth surfaces such as polished glass," says Kellar Autumn, lead author of an article in this week's Proceedings of the National Academy of Sciences. Our new data prove once and for all how geckos stick."

Working at Lewis & Clark College, the University of California at Berkeley, the University of California at Santa Barbara, and Stanford University, the interdisciplinary team:

• confirmed speculation that the gecko's amazing climbing ability depends on weak molecular attractive forces called van der Waals forces,

• rejected a competing model based on the adhesion chemistry of water molecules, and

• discovered that the gecko's adhesive depends on geometry, not surface chemistry. In other words, the size and shape of the tips of gecko foot hairs--not what they are made of--determine the gecko's stickiness.

To verify its experimental and theoretical results, the gecko group then used its new data to fabricate prototype synthetic foot-hair tips from two different materials.

"Both artificial setal tips stuck as predicted," notes Autumn, assistant professor of biology at Lewis & Clark College in Portland, Ore. "Our initial prototypes open the door to manufacturing the first biologically inspired dry, adhesive microstructures, which can have widespread applicatio
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Contact: Jean Kempe-Ware
kempe@lclark.edu
503-768-7963
Lewis & Clark College
26-Aug-2002