snugtop Posted August 31, 2005 Posted August 31, 2005 Gravity-Defying Geckos Teach Scientists a Lesson By DENISE GRADY Published: August 30, 2005 THE NEW YORK TIMES The scientific quest to make artificial gecko feet has taken a leap forward. Geckos, lizards that are notorious for their sticky feet, can run up walls and across ceilings, and hang tauntingly by one toe. They have no suction cups, hooks or glue on their feet, so how do they do it? The soles of geckos' feet are covered by 500,000 minute hairs, and the tip of each hair splits into hundreds more. Top, a lizard's hairs are magnified 595 times. Five years ago, researchers at the University of California, Berkeley; Stanford; and Lewis and Clark College found the secret: 500,000 minute hairs cover the sole of each foot, and the tip of each hair splits into hundreds more. The hairs are so elastic that they can bend or squish to conform to microscopic nooks and crannies under the creature's feet, even on the glass walls of an aquarium. As a result, the tiny hairs touch so much surface area so closely that weak forces of attraction between molecules in the hairs and in whatever surface the animal is walking on add up and become sufficient to let the gecko hang on. The connection breaks when the gecko shifts its foot enough to change the angle between the hairs and the surface. The discovery intrigued scientists, who immediately realized that if synthetic gecko-foot hairs could be made, they might be a great adhesive - strong, glue-free, dry, reusable and, unlike suction cups, capable of working in a vacuum like outer space. Engineers envisioned robotic instruments that could climb walls or grab objects without dropping them, and rovers that could maneuver rugged terrain on distant planets. Such adhesives could also be used to stick components together in electronic devices. The National Science Foundation takes these ideas so seriously that it gave a $400,000 grant to scientists at the University of Akron and Rensselaer Polytechnic Institute to try making imitation gecko feet. In a recent issue of the journal Chemical Communications, the team reported that it had indeed produced synthetic hairs, with 200 times the sticking power of the ones made by nature. Although the scientists have tested only minute amounts of the material, they estimate that if its properties hold up on a larger scale, a dime-size patch of it could support 2 to 22 pounds, depending on how densely the hairs were packed. "Think of it almost like nano-Velcro," said Ali Dhinojwala, an associate professor of polymer science at the University of Akron. The synthetic hairs - one ten-thousandth the width of a human hair - are made of highly flexible carbon cylinders, or nanotubes, embedded in a plastic base like bristles in a hairbrush. The tubes are strong and practically unbreakable, Professor Dhinojwala said, adding that other groups had tried making the tubes of plastic, but it turned out to be too weak. He said people had asked him whether the new material could be fashioned into gloves and shoes for rock climbers. "I'm a little hesitant on going too fast," Professor Dhinojwala said. "Nature has had more time than we have had. I would hesitate to extrapolate. But the imagination is there." Quote
Cobra_Commander Posted August 31, 2005 Posted August 31, 2005 put a cork in it you self-righteous prick Quote
catbirdseat Posted August 31, 2005 Posted August 31, 2005 The question must be asked how to deal with the issue of contamination. Surely anything that adheres to surfaces would also attract particles and quicky lose its sticky qualities. One should ask how does the gecko manage this? Are the hairs shed regularly so as to renew the surface? Quote
snugtop Posted August 31, 2005 Author Posted August 31, 2005 I suspected that a topic as rich and sprayastic as gecko nano hairs would have been played out in spray before...I did a search on "gecko" before I posted that but it yielded no results...WTF? Come to think of it, I've never been able to find anything using the Search function. Quote
catbirdseat Posted August 31, 2005 Posted August 31, 2005 This has been sprayed about before, to be sure. Gecko hairs are aid. Quote
Dru Posted August 31, 2005 Posted August 31, 2005 ...WTF? Come to think of it, I've never been able to find anything using the Search function. Have you tried asking Googlebot to help you? Quote
snugtop Posted August 31, 2005 Author Posted August 31, 2005 I don't know who this imposter is but I am the original Googlebot. Sureamnodder. Quote
MatthewS Posted August 31, 2005 Posted August 31, 2005 WTF? Come to think of it, I've never been able to find anything using the Search function. I think the default search only looks for messages newer than 1 week - you need to change that to look for older posts. Quote
Dru Posted August 31, 2005 Posted August 31, 2005 Maybe the Search function is too busy looking for the Nodder to deign to find trivial things for you or me. Quote
Squid Posted August 31, 2005 Posted August 31, 2005 put a cork in it you self-righteous prick Someone forget to lube your joints this morning? ps. in the future, you may address me as "Your Holiness, the Squid". Complaints can be directed to the appropriate department. Quote
olyclimber Posted August 31, 2005 Posted August 31, 2005 Squid, how come you haven't responded to the insult I hurled at you in one of the threads below yet? Get on it! Quote
Squid Posted August 31, 2005 Posted August 31, 2005 I'm slacking on the spray. Could you post a link? Quote
Stefan Posted August 31, 2005 Posted August 31, 2005 The question must be asked how to deal with the issue of contamination. Surely anything that adheres to surfaces would also attract particles and quicky lose its sticky qualities. One word. Teflon! Quote
olyclimber Posted August 31, 2005 Posted August 31, 2005 I'm slacking on the spray. Could you post a link? http://www.cascadeclimbers.com/threadz/showflat.php/Cat/0/Number/494014/an/0/page/0#494014 Quote
Squid Posted August 31, 2005 Posted August 31, 2005 I read the thread, but I couldn't figure out where I was supposed to be insulted. Could you be more specific? Quote
archenemy Posted August 31, 2005 Posted August 31, 2005 The question must be asked how to deal with the issue of contamination. Surely anything that adheres to surfaces would also attract particles and quicky lose its sticky qualities. One word. Teflon! How does Teflon to stick to the pan? Quote
TrogdortheBurninator Posted September 1, 2005 Posted September 1, 2005 The question must be asked how to deal with the issue of contamination. Surely anything that adheres to surfaces would also attract particles and quicky lose its sticky qualities. One word. Teflon! How does Teflon to stick to the pan? sintering Quote
TREETOAD Posted September 1, 2005 Posted September 1, 2005 whatefer happened to that little bastard Rush Limbaugh Quote
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