Robot roaches would be a benefit, not a pest

David Downs, Special to The Chronicle

Saturday, December 26, 2009


One day a tiny robotic cockroach could save lives.

UC Berkeley engineers driven by such a vision are ebullient this winter over DASH - a cheap, lightweight, six-legged robotic cockroach that can survive a four-story drop, crawl over objects twice its height and run for an hour on special watch-size batteries.


"It's something remarkably simple that does something remarkably complex - just like nature," said Erico Guizzo, a robotics expert and associate editor at the engineering publication IEEE Spectrum.

Built by a UC graduate student with grant money from the National Science Foundation, the speedy, boxy, 16-gram beast consists of just paperboard and Radio Shack electronics. His descendants will eventually crawl through collapsed buildings and freeways, searching places too dangerous for first responders to tread.

DASH stands for dynamic autonomous sprawled hexpod. It is the latest invention of the university's Biomimetic Millisystems Lab, a research center famous for its work with geckos. The lab discovered that geckos can run up vertical surfaces thanks to millions of tiny little hairs on their feet. Now they're enhancing nature's technique for human needs, a goal at the heart of biomimetics.

At a time when UC budgets are shrinking, the field of biomimetics is exploding. The lab will add staff in 2010, working toward robots that could be used for the next conflict, Bay Bridge malfunction or the Big One.

Inspired by a quake
Dr. Robert Full, UC professor of integrative biology who did the basic animal research that went into DASH's gait, said the inspiration for such work goes back to the 1989 Loma Prieta earthquake and the search-and-rescue operations that followed.

"That's one of the first things that motivated me," Full said. "You'd see these people climbing into these dangerous areas not even knowing if a person's in there - this incredible heroism - and I thought, 'Why don't we get robots that can do this?' "

Paul Birkmeyer, the UC graduate student who made DASH out of less than $50 worth of materials, envisions pouring a garbage can of hundreds of small, cheap robotic cockroaches into the rubble of a catastrophe. They'd seek the lowest ground, and their sensors would sniff for carbon dioxide, the telltale signature of survivors.

"Basically, right now, you just have to randomly dig and hope you find people," Birkmeyer said. "If you could send these tiny robots in who say, 'Hey, we found this person. Dig at this exact spot and you'll find them' - who cares if the robots don't make it back?"

DASH represents a startlingly successful step down that path, said Professor Ron Fearing, head of the Millisystems lab. DASH is simpler, lighter and more rugged than anything in development.

"It worked great. Usually, we make things and they don't work as well as we expect," he said. "It's a combination of the design choices that Paul made, plus the materials, plus the underlying physics that made this thing work in a really cool way."

A precision, computer-guided laser cuts DASH from a single piece of paperboard. Birkmeyer then hand-folds the paperboard into a shape like an origami insect. The folds create six legs, a boxy body and a simple drive that attaches to a DC motor. The first motor came from a toy bat at Radio Shack called Vamp. The final design evolved over 18 months and about three dozen versions, Birkmeyer said.

An animal discovery
DASH gains its speed and stability from locomotion principles extracted by Full from real cockroaches. Using high-speed cameras and animal treadmills, Full discovered that all animals - from insects to man - have the same leg stiffness relative to their weight. Adjust stiffness to weight and you gain the inherent stability of living legged systems.

"When we first discovered this, we said, 'We don't know why this is true, but we should try this in robots,' " Full said.

In 2010, Fearing intends to shrink DASH to just 2.5 grams, while Birkmeyer goes to work on getting small robots to scale vertical walls. Simple-legged automatons should be doing mankind's dangerous work in three to five years, Fearing said.

"I think it's just the beginning," Full said. "We're going to see running robots, flying robots, robots swimming and doing everything else."

From: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/12/26/BALE1B9FJ4.DTL