The vile cockroach, one of the most despised creatures on the planet, has become the latest darling among researchers who are trying to emulate its maneuverability and economy of locomotion in the search for the perfect robot.
But the nasty cockroach is incredibly complex and it is yielding its secrets very grudgingly, to the consternation of engineers from coast to coast. Why are they so intrigued with an ugly animal that can scamper across a kitchen floor and disappear under the stove the instant the light is turned on?
Because the cockroach, it turns out, has great legs.
"Cockroaches are just amazingly stable and robust when they are running," engineering professor John Schmitt of Oregon State University said in a telephone interview. Schmitt, along with many other researchers, is trying to figure out how the cockroach can zip over a maze of blocks, some three times the height of its hips, and never miss a step.
What's amazing, Schmitt said, is the cockroach doesn't even have to think about it. That's important to robotics researchers, because the current generation of robots use so much of their energy just figuring out how to maneuver around obstacles that there's precious little juice left to do anything else.
"If we could replicate the behavior of the cockroach, that would be incredible because we would be able to make running robots that really wouldn't have to think so much about the terrain they are running over, which would allow them to use that processing power for something different," he said.
Researchers are turning to animals with legs partly because robots that depend on wheels for maneuverability can get trapped too easily, like the Mars Sojourner that got stuck against a rock in 1997. If the Sojourner had only had legs, these researchers believe, it might have been able to just step over the rock and continue on.
Many animals have inspired researchers to produce mechanical crickets, and robotic spiders, and even flying insects, but there's something special about cockroaches. A couple of years ago, researchers found that if a cockroach misses a step while scurrying across rugged terrain, it doesn't stop to see what when wrong, it just continues on its course.
However, if it comes up against a huge obstacle, it has to stop and change its behavior, so it's capable of figuring out a new course when the situation demands it, but not when it doesn't have to.
That allows the roach to move rapidly without devoting too much of its "processing power" to locomotion. And by the way, a cockroach can really move, in some cases up to 50 times its body length in just one second. It can also dodge a bullet, as anyone knows who has tried to swat one with a newspaper.
And it can do all that with very little nourishment. Cockroaches have been known to survive on nothing more than the glue on the back of a postage stamp. Some species can live 45 minutes without air, and completely underwater for 30 minutes. They are so durable that some scientists have suggested that when global nuclear war finally comes, only cockroaches will survive.
But it's their ability to run over rough terrain that has researchers mesmerized.
Schmitt is collaborating with Jonathan Clark, a mechanical engineering professor at Florida State University, who studied under a leader in the field, Mark Cutkosky of Stanford University. Cutkosky has actually built robots that walk on six legs, based partly on research by Robert Full of U.C. Berkeley, an expert on animal locomotion.
Cutkosky's robots work, but they are no match for a cockroach. Or a gecko, that can walk across the ceiling, much like a cockroach. That has intrigued Clark, because the two animals are so dissimilar, yet they move in a "dynamically similar manner," according to Clark, who has built robots that can climb, sort of like a gecko.
Lots of animals are providing what Schmitt calls "bioinspiration" to scientists and engineers, who marvel at how even some relatively simple organisms can do complex maneuvers, seemingly with little effort. But Schmitt's true love remains the cockroach.
"Cockroaches are incredible," he said. "They can run fast, turn on a dime, move easily over rough terrain, and react to perturbations faster than a nerve impulse can travel."
Schmitt said he is optimistic that he will live to see the day when bioinspiration allows engineers to mimic the maneuverability of a roach.
He sees hundreds of robotic roaches, scampering across a battleground, climbing effortlessly over debris, and wasting so little energy on locomotion that they can blanket the area with a wireless communications network. Or they might detect land mines, saving countless lives, or warn of the presence of biological hazards.
That's a tall order to fill, even for a cockroach.