Robert Full, a biologist at the University of California, Berkeley, insists biomimicry isn't all about plundering the natural world. He has worked with engineers since the mid-1990s when he helped to develop the crab-inspired Ariel, a minesweeping robot made by iRobot Corp. (famous for its Roomba robotic vacuum) that can look for buried explosives in surf zones. Rather than just aping what nature provides, he says, he encourages designs that "use the advantageous principles and analogies that you find in nature and integrate them with engineering to make something better than nature." Evolution, he says, is not the ultimate engineer; rather, it works on the "good enough" principle—making incremental improvements on previous designs instead of starting from scratch to build better ones.

Last year, Full co-founded the Center for Integrative Biomechanics in Education & Research (CiBER) at U.C. Berkeley to foster mutualism between biologists and engineers: The former provide mechanisms that the latter can use on their devices, which then may serve as models to advance biology. Stickybot, which Full collaborated on with Stanford's Cutkosky, probably best exemplifies that principle.

In 2003 the Defense Advanced Research Projects Agency (DARPA), the Pentagon's advanced research arm, spent several million dollars to commission the building of a robot that could climb walls for surveillance purposes. The result was Spinybot, which could ascend rough surfaces like trees and cement walls with the aid of microclaws tipped with tiny spines, a mechanism borrowed from insects like the cockroach. Stickybot, which debuted in 2006 and can walk up smooth surfaces like windows, uses an adhesive inspired by geckos. On their feet, the lizards have millions of setae—essentially hairs with split ends—that use intermolecular forces to accomplish "directional adhesion": If their setae encounter a surface moving in one direction—say, going left to right—they adhere; when going the opposite direction, they peel off. "It's like Scotch tape that you don't have to press down to stick it," Cutkosky says.

Engineers noted that their climbing robots fell of walls if they didn't have a tail. "We thought [geckos] never use their tail," Full recalls, but it turns out they do. The rear appendage helps the reptiles stabilize themselves and keep their heads from moving back, causing them to fall head over tail to the ground.

Determining that little piece of biophysics, however, required the building of a robot. "That's where biomimetics is moving," Full says. "It's more than cursory and superficial advice on design."