Complexity Digest 2008.06 - 17.04

08-Feb-2008

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Engineers Create New Adhesive That Mimics Gecko Toe Hairs, PhysOrg.com Bookmark and Share

Excerpts:
The gecko-inspired adhesive can support significant weight. Increasing weight increases contact area for the adhesive (contact area is the bright area near the top of the patch). As the load increases, more fibers are recruited to make contact, increasing the strength of the adhesion parallel to the surface. When the sliding force is removed, the fibers straighten, and the patch is easily released with negligible pull-off force. The patch has demonstrated better than 1/6 of a real gecko's stress on the same glass surface. Credit: J. Lee and R.S. Fearing, UC Berkeley
A new anti-sliding adhesive developed by engineers at the University of California, Berkeley, may be the closest man-made material yet to mimic the remarkable gecko toe hairs that allow the tiny lizard to scamper along vertical surfaces and ceilings. (...)

Taking a cue from the millions of hairs covering a gecko's toes, researchers squeezed 42 million hard plastic microfibers onto each square centimeter of material and loaded it with various weights. They found that on a smooth, clean, vertical surface, two square centimeters of the synthetic adhesive could hold 400 grams (0.88 pounds). At the same time, the adhesive easily lifts off with minimal force and no residue.
Editor's Note: But does that explain how Geckos walk upside-down across the ceiling?