A team led by Physicist Kellar Autumn of Lewis and Clark College in Oregon and engineer Ronald Fearing of the University of California at Berkeley has figured out how a gecko lizard, below, can scramble up walls and do vertical hangs—and they are hoping to put that insight to use for humans.
The gecko's clinging power lies in the roughly 6.5 million tiny hairs on its feet. Each hair binds to surfaces because of the weak bonds that result from attractions between molecules, known as van der Waals forces. Using this information, the team figured out how to fashion synthetic gecko nano-hairs from two different plastics—silicone rubber and polyester. The researchers determined that their artificial gecko hairs stuck to various surfaces just as well as the real ones, which can hold 200 pounds per square inch of hair-covered material. But will humans ever be able to scale tall buildings and cliff facades like a certain cartoon crime fighter? "I can't watch Spider-Man without thinking we'll do that someday," says Autumn. Meanwhile, he envisions many non-superhero uses, including adhesives on space suits.
Photograph courtesy of Kellar Autumn.