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Gecko biomimicry produces adhesive better than the real thing Nanotube Adhesive Sticks Better than a Gecko's Foot University of Akron June 19, 2007
In a paper published in the June 18—22 issue of the Proceedings of the National Academy of Sciences, the researchers describe a process for making polymer surfaces covered with carbon nanotube hairs. The nanotubes imitate the thousands of microscopic hairs on a gecko's footpad, which form weak bonds with whatever surface the creature touches, allowing it to "unstick" itself simply by shifting its foot. For the first time, the team has developed a prototype flexible patch that can stick and unstick repeatedly with properties better than the natural gecko foot. They fashioned their material into an adhesive tape that can be used on a wide variety of surfaces, including Teflon. Pulickel Ajayan, the Henry Burlage Professor of Materials Science and Engineering at Rensselaer, and Lijie Ci, a postdoctoral research associate in Ajayan's lab, created the material in collaboration with Ali Dhinojwala, professor of polymer science at the University of Akron, and University of Akron graduate students Liehui Ge and Sunny Sethi.  Courtesy of the University of Akron. Microfabricated aligned multiwalled carbon nanotube setae and spatulas. (A) Optical picture of gecko foot showing that the setae are arranged in many lobes along the foot. (B) SEM image of natural gecko setae terminating into thousands of smaller spatulas. (E--H) SEM images of synthetic setae of width 50 (E), 100 (F), 250 (G), and 500 (H) um. (C and D) Side views (C) and higher magnification SEM image (D) of the 100 um setae. "Several people have tried to use carbon nanotube films and other fibrous structures as high-adhesive surfaces and to mimic gecko feet, but with limited success when it comes to realistic demonstrations of the stickiness and reversibility that one sees in gecko feet," Ajayan said. "We have shown that the patchy structures from micropatterned nanotubes are essential for this unique engineering feat to work. The nanotubes also need to be the right kind, with the right dimensions and compliance." "Geckos inspired us to develop a synthetic gecko tape unlike any you'll find in a hardware store," Dhinojwala says. "Synthetic gecko tape uses ‘van der Waals interactions' — the same interactions that hold liquids and solids together — to stick to a variety of surfaces without using sticky glues." The material could have a number of applications, including feet for wall-climbing robots; a dry, reversible adhesive in electronic devices; and outer space, where most adhesives don't work because of the vacuum. The research was funded by the National Science Foundation. Related
(7/7/2008) By studying and mimicking the characteristics of the flippers, fins and tails of whales and dolphins, engineers have devised more a efficient way to generate wind power, reports a researcher presenting at the Society for Experimental Biology's Annual Meeting in Marseille, France. Future cities will be more like ecosystems that enrich society and the environment (5/28/2008) As The World Science Festival continues in New York this week, specialists in vastly diverse fields across scientific disciplines are coming together to talk about ideas, problems and solutions. From Astronomy to Bioacoustics, the dialogues about challenges and opportunities are rich and inspiring. At the front of this year's festival rests the issue of sustainability and how scientists, specialists and society will address the imminent environmental and economic trials we are sure to face in a rapidly changing and uncertain world. Squid beaks may revolutionize engineering (3/27/2008) When scientists dissect the stomachs of sperm whales, they find the super-hard beaks of squids, the only part of them that is indigestible. Scientists can tell the diet of a whale by the variety of beaks left behind, sometimes numbering in the thousands. But how does a squid, whose body is soft and supple, have a beak that is considered one of the hardest organic materials in natures? Scientists have long pondered this question. How falling a gecko lands on its feet (3/17/2008) According to new research the gecko may have the most dynamic tail in the natural world. Two researchers from UC Berkley have discovered that the gecko uses its tail to keep itself from falling off slippery vertical surfaces and when falling to rapidly right itself. So, like a cat, it always lands on four feet. Biomimicry of sea cucumber skin may help stroke treatment (3/6/2008) Using sea cucumber skin for design inspiration, scientists have developed a new material that may improve treatment for Parkinson's disease, stroke and spinal chord injuries. The research is published in the journal Science. Comments? News options News index | RSS | News Feed Advertisements: Organic Apparel from Patagonia | Insect-repelling clothing |
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