A lizard's sticky feet inspire a strong new adhesive.
In the movie Spider-Man, actor Tobey Maguire makes climbing up walls and hanging out on the ceiling look easy—thanks to special effects. In future movies, though, actors and stunt doubles might really be able to crawl along walls and ceilings. All they'll need is some "gecko tape."
The hand of this Spider-Man toy is covered with gecko tape, allowing it to hang from the ceiling.
|Andre Geim/Univ. of Manchester|
So far, scientists in England and Russia have made just 1 square centimeter of this new adhesive. But the nickel-sized patch can support as much as 3 kilograms of weight. If you could cover the palm of your hand with gecko tape, you could stick yourself to the ceiling.
The tape is a simple version of the adhesive on a gecko's feet. The soles of the lizard's feet are covered with millions of tiny little hairs, too small to see with the naked eye. The molecules in these hairs snuggle up to the molecules of any surface the gecko walks on. The molecules are attracted to each other, forming a temporary bond that keeps the gecko firmly in place.
An array of tiny plastic pegs mimics the microscopic structure of a gecko's sticky sole.
The gecko tape works on the same principle. It is a thin piece of plastic covered with millions of microscopic, plastic hairs that hold on tight when pressed against a surface.
But there's a problem. Gecko tape does not last as long as gecko feet. After applying and removing the tape a few times, it starts to lose its sticking power. Researchers are going to try making the microscopic tape hairs out of a different material. If they get it right, "hanging out" will have a whole new meaning.—S. McDonagh
McDonagh, Sorcha. 2003. Available at Caught on tape: Gecko-inspired adhesive is superstrong. Science News 163(May 31):341. Available at http://www.sciencenews.org/20030607/fob3.asp .