Volume 3, Issue 19 March 2006
Robobugs, Gecko Tape, and Nature's Inspiration
The National Academies named Robert Full a National Academies Education Mentor in the Life Sciences 2005-2006. (Photo ©2000 Peter Menzel, from Robo sapiens: Evolution of a New Species (MIT Press))
In the last four billion years, Mother Nature has evolved some amazing feats in engineering. That's why UC Berkeley professor Robert Full spends so much time studying how cockroaches, crabs, lizards, and other creepy-crawlies move through the world. His groundbreaking research on animal locomotion not only deepens our understanding of biology but has also inspired such wonders as a mechanical crab, robotic cockroach, and self-cleaning adhesive tape based on a gecko's foot.
"Our motto is 'diversity enables discovery,'" says Full, a professor of integrative biology. "We look at a very diverse group creatures and see if we can extract principles from them that engineers can use to build things that weren't possible before."
Full's laboratory looks like a gymnasium as imagined by the animators of A Bug's Life, an animated film that Full consulted on. Centipedes and rhino beetles run in place while high-speed videocameras capture their gaits at 1,000 frames per second. (Years ago, the researchers were surprised to find that nearly every animal they studied moves with the same bouncing pattern as humans.) A highly-sensitive scale measures the force of a carpenter ant's step. A vertical, clear treadmill, dubbed the "geckomill," enables the researchers to closely observe how a gecko's foot firmly attaches and then peels off a smooth surface.
Full put a centipede through a treadmill workout. (Photo ©2000 Peter Menzel, from Robo sapiens: Evolution of a New Species (MIT Press))
"We also study animals at the extremes of performance, creatures that are exceptionally good at one particular thing," Full says.
For example, Full has long been intrigued by the millions of microscopic hairs on a gecko's toes that act as an incredibly-strong adhesive, providing them with their climbing prowess. Indeed, Full is actively working with several engineers, including Berkeley's Ron Fearing, to develop an artificial gecko adhesive comparable to its natural inspiration. The material could be used in everything from robotics to a new kind of Band-Aid.
Most recently though, Full and his students have been helping Stanford University professor Mark Cutkosky and University of Pennsylvania professor Daniel Koditschek build robots that can climb walls. In the future, these mobile robots might seek out survivors in buildings submerged during a flood or search for hidden explosives in the rubble of war zones.
Inspired by Full's discoveries about how cockroaches run, the RHex robot was built at the University of Michigan. (courtesy Daniel Koditschek, University of Michigan)
"Again, we looked at the world's greatest climbers, the Geckos," Full says. "At first, we thought it was just the amazing foot that enables them to grab onto anything. But as we worked with the engineers while they were building the robot, we found some general patterns of movement in the legs of Geckos and insects that we hadn't seen before. So Mark and his team put them in the robot."
The resulting shoebox-size robot doesn't resemble a lizard or a bug, but it can easily scurry up and down a tree or concrete wall. Arrays of tiny spines on the robot's feet catch on to microscopic rough spots on the wall. Those spines combined with the carefully choreographed motion of the feet and limbs inspired by Full's animal studies enable the robot to get a good foothold without sacrificing speed.
"It doesn't look like any real animal, but all of the principles are there," Full says.
As the engineers fine-tune their robot, they're also providing feedback to Full on what his group may look for in their own research. For example, the robot's stability is dependent on a "tail" structure that the Stanford team added. Full says his group will look at their animals to determine why this may be necessary. In fact, he says this cross-pollination of ideas across disciplines, from biology to mathematics to engineering, is the key to progress.
Full's discoveries also inspired the design of the climbing robot RiSE built in collaboration by Stanford University, the University of Pennsylvania, and Boston Dynamics. (courtesy the researchers)
"Everyone can advance their own field, but through synergy, the research accelerates and collectively we can create something that no single group could ever do," Full says.
This multidisciplinary approach is at the heart of a new Berkeley research center Full is directing. CIBER is a dual acronym, he explains, standing for both the Center for Integrative Biomechanics in Education & Research and also the Center for Interdisciplinary Bio-inspiration in Education & Research. The former references the research focus of this particular center. The latter name, Full explains, is a call for a new paradigm where research and education are inseparable. Only if students actually work together across disciplines on real world problems can they ever hope to truly learn from nature and surpass her in our applications, he says.
"Evolution works on the just-good-enough principle," Full says. "So we want to learn how to mesh advantageous principles from biological systems with the best human engineering to actually build things that are better than nature."