Mark Cutkosky at Stanford University's Biomimetics and Dextrous Manipulation Lab
2 ft. long and weighs 1 lb.
To learn how to climb walls, Stanford roboticist Mark Cutkosky turned to the best wall climbers around: geckos. To create nonsticky adhesive materials, geckos showed the way to van der Waals force, the sum total of attracting or repelling forces between molecules. "The trick is that it's not very strong, and it only works over very, very short distances," Cutkosky says. What he means by very short is molecular-length scales. If you can make van der Waals forces work for you, as Cutkosky has, you can climb nearly any surface. One secret behind it is directional adhesion, and, as Cutkosky points out, geckos have it. "If you feel their little feet, they don't feel sticky at all. But as soon as you pull on it, suddenly it grabs. Our adhesives work the same way. And it makes all the difference." The most recent version of Stickybot is a bit bigger, with 19 microprocessors that are responsible for moving the joints. Bigger means heavier, so Stickbot needed a bigger tail for balance if the first two legs miss a step. "If you think about most animals that climb really well," says Cutkosky, "almost all of them have tails."
See Stickybot in action