Nonskid surface

Inspired by the gravity-defying gecko, researchers at the University of California at Berkeley have concocted an array of microfibers that can keep objects from sliding down near-vertical surfaces!

That quarter isn't going anywhere. With 42 million fibers per square centimeter, the array (sandwiched between the quarter and the slide) holds the coin in place through van der Waals forces, a bond that forms between two molecules when they are close to each other. Van der Waals forces also keep ice stuck to glass. The array, however, isn't sticky or goopy.

At other universities, researchers are tinkering with van der Waals forces to remove ice from windows or create carbon nanotube memory chips.

Through their feet, geckos get both friction, which keeps them from sliding down, and adhesion, which makes it difficult to pull them off a surface. Scientists hope to better understand the forces behind gecko feet and replicate the principles in products.

The microfiber array developed at U.C. Berkeley doesn't exhibit adhesion. Thus, a suit of the material would not let you do Spider-Man stunts, but it would probably hold you up much better than a Velcro sweat suit. Nonetheless, as a high-friction surface, microfiber arrays could be incorporated into athletic shoes and tires.

Source: news.com.comAdded: 11 October 2006