EVANSTON, Ill. -- Geckos are remarkable in their ability to scurry up vertical surfaces and even move along upside down. Their feet stick but only temporarily, coming off of surfaces again and again like a sticky note. But put those feet underwater, and their ability to stick is dramatically reduced.
Water is an enemy of adhesives, which typically do not work well in wet environments -- think of how long a bandage on your finger lasts. Now two Northwestern University biomedical engineers have successfully married the geckos adhesive ability with that of an animal well known for its sticking power underwater: the mussel.
Combining the important elements of gecko and mussel adhesion, the new adhesive material, called geckel, functions like a sticky note and exhibits strong yet reversible adhesion in both air and water.
The findings, which could lead to applications in medical, industrial, consumer and military settings, will be published as the cover story in the July 19 issue of the journal Nature.
The geckel material should be useful for reversible attachment to a variety of surfaces in any environment, said Phillip B. Messersmith, professor of biomedical engineering at Northwesterns McCormick School of Engineering and Applied Science and an author of the paper.
I envision that adhesive tapes made out of geckel could be used to replace sutures for wound closure and may also be useful as a water-resistant adhesive for bandages and drug-delivery patches. Such a bandage would remain firmly attached to the skin during bathing but would permit easy removal upon healing.
A geckos strong but temporary adhesion comes from a mechanical principle known as contact splitting. Each gecko foot has a flat pad that is densely packed with very fine hairs that are split at the ends, resulting in a greater number of contact points than if the hairs were not split. (The diameter of one of the split hairs is as small as 2
Contact: Charles Loebbaka