National Geographic : 2008 Apr
make Stickybot climb better. Then he noticed in a paper on gecko anatomy that the lizard had branching tendons to distribute its weight evenly across the entire surface of its toes. Eureka. "When I saw that, I thought, Wow, that's great!" He subsequently embedded a branching polyester cloth "tendon" in his robot's limbs to distribute its load in the same way. Stickybot now walks up vertical surfaces of glass, plastic, and glazed ceramic tile, though it will be some time before it can keep up with a gecko. For the moment it can walk only on smooth surfaces, at a mere four centimeters per second, a fraction of the speed of its biological role model. The dry adhesive on Stickybot's toes isn't self-cleaning like the lizard's either, so it rapidly clogs with dirt. "There are a lot of things about the gecko that we simply had to ignore," Cutkosky says. Still, a number of real-world applications are in the offing. The Department of Defense's Defense Advanced Research Projects Agency (DARPA), which funds the project, has it in mind for surveillance: an au tomaton that could slink up a building and perch there for hours or days, monitoring the terrain below. Cutkosky hypothesizes a range of civilian uses. "I'm trying to get robots to go places where they've never gone before'"he told me. "I would like to see Stickybot have a real world function, whether it's a toy or another application. Sure, it would be great if it eventu ally has a lifesaving or humanitarian role...." His voice trailed off, in a wistful, almost apologetic tone I had heard undercutting the optimism of several other biomimeticists. For all their differences in background, temperament, and ultimate aims, most practitioners conclude their enthusiastic discourses on their bio-inspired invention with a few halfhearted theories on how it may someday make its way into the real world. Often it sounds like wishful thinking. For all the power of the biomimetics para digm, and the brilliant people who practice it, bio-inspiration has led to surprisingly few mass-produced products and arguably only one household word-Velcro, which was invented in 1948 by Swiss chemist George de Mestral, by copying the way cockleburs clung to his dog's coat. In addition to Cutkosky's lab, five other high-powered research teams are currently trying to mimic gecko adhesion, and so far none has come close to matching the lizard's strong, directional, self-cleaning grip. Likewise, scientists have yet to meaningfully re-create the abalone nanostructure that accounts for the strength of its shell, and several well-funded The flutter of the micromechanical flying insect (right) doesn't yet match the complex U-shaped motion achieved by its living muse, the blowfly. But the robot could soon take flight untethered. Powered by tiny electric actuators along its sides, the bot's fragile wings beat up to 275 times per second, even faster than the bug's that inspired it. "A true fly's wings are remarkable, rotating in every stroke," says UC Berkeley's Ron Fearing. "Our challenge is to get a working mechanism in a device one-twentieth the weight of a paper clip."