Able to climb and crawl where other robots can’t, ‘snakebots’ could have both small and large applications
In a lab in the basement of Newell-Simon Hall, robotics doctoral student Matt Tesch grabs what looks like a PlayStation controller and begins quickly pressing buttons and moving the joysticks. A serpentine robot, about two-feet-long and with 16 distinct segments or modules, slithers across the floor like a snake. It stops for a moment and then begins crawling sideways, much like a sidewinder.
After the snakebot crawls on the floor for a bit, showing off all its moves, Tesch grabs a hollow plastic tube, wraps the snakebot around the pole and it rolls upward. After it reaches the top, he takes it off the tube and straightens it out.
He feeds about half of it into the tube, and it inches down slowly.
“We control the motion by sending waves through the joints,” he says.
Tesch is demonstrating a snakebot’s means of locomotion. They can slither backward, crawl through tiny openings and navigate sharp bends, which comes in handy for inspecting pipes. In fact, one recently showed how well it crawls at a nuclear power plant in Austria.
In May, a snakebot slithered through pipes and vents in the never-activated Zwentendorf Nuclear Power Plant, west of Vienna on the south bank of the Danube River. The tests gave researchers an opportunity to access pipes and areas that would be restricted because of high radiation levels in working plants, allowing the robot to go where no robot has gone before.
“Think of how they could have been used at Fukushima,” says Howie Choset, director of the CMU Biorobotics Lab, referring to the Japanese nuclear power plant that melted down in 2011 following an earthquake and tsunami. Radiation levels in much of the plant remain so high that humans can’t enter, and the company that owns the Fukushima Daiichi plant has recently admitted that it doesn’t know where the melted fuel cores are.
But perhaps a snakebot could.
Choset has been developing snakebots for almost two decades. Over the past few years they’ve broken into the public consciousness—and in a big way. Videos of the amazing snakebots from Choset’s lab are going viral, capturing the attention of bloggers and journalists for Popular Science, Bloomberg Businessweek and NPR.
This year’s Austrian tests happened almost through a happy set of coincidences. The Zwentendorf nuclear plant was built in the 1970s. Public opposition to starting the plant meant that it was never commissioned, and instead it’s used for training and educational purposes. Florian Enner, a research associate and software engineer in the Biorobotics Lab, is from Salzburg, Austria, and following a conference in Germany, he asked officials if the snakebot team could do some research at Zwentendorf. To the team’s surprise, the power company that owns Zwentendorf agreed, giving the CMU group access for two entire days.
“In the lab we sort of know what to expect,” Enner says. “There, we didn’t know what we would find.” As the snakebots crawled through the pipes, they used LED lights and cameras to show the researchers where they were and what they saw. They encountered lost bolts that had lain undetected inside conduits for so long they were rusted to the sides. They found long-forgotten sensors protruding into the pipes.
The snakebots’ cameras are able to automatically correct the view presented—when they’re upside down, the cameras adjust the video to appear right side up. That feature impressed the power plant’s staff, the researchers say, but more impressive was the robots’ flexibility, which gives them a serious advantage over conventional equipment for inspecting the insides of pipes. Current pipe inspection tools cannot turn corners. When they encounter a sharp bend, workers have to cut a hole in the pipe and push the robot through. It’s awkward, causes damage to pipes and exposes workers to potentially dangerous situations.
A segmented snakebot can easily twist and turn up and into inlets and through tight corners, allowing researchers to be far enough away from dangers such as radiation. (Tesch and Enner have pictures of themselves with the Zwentendorf plant’s steel containment vessel. If the plant were active, they’d never had been able to get so close.)
Inspecting power plants is only one of the many tasks Choset’s snakebots can perform. The robots are effective in search and rescue—snakebots can easily slither between fallen debris in crumbled buildings after a disaster. And snakebots can go places where ladders can’t be used. A rescuer, for instance, can throw the robot at a pole. It grabs the pole, coils around it, and crawls upwards. At a dangerous building, first responders could toss in a snakebot and have it send back images of the scene before humans risk their lives.
“They work well if you want to reach a great distance and thread through tight spaces,” Choset says. “Urban search and rescue use extends your sensory reach to find survivors while protecting first responders.”
Another version of the snakebot—much smaller—is being tested in cardiac heart operations. For many heart procedures, doctors must crack the sternum to access the heart. A simple test could mean a week’s stay in the hospital. But with a snake robot, the same procedures can become minimally invasive. The snakebot can enter a small incision, make a quarter-inch turn, and weave behind the heart, where it can send photos back to physicians. The technology has already been successfully tested on animals. Choset believes that snakebots eventually could allow technicians to perform common procedures that currently require surgeons.
“What’s provocative is that we can have non-surgeons deliver care, and, it may not require a hospital stay,” he says. “Snakebots could decrease the cost of surgery. And robots could create new jobs.”
These robots of the future have gone into the past, too. Prior to the recent Egyptian revolution, Choset took a snakebot to an archeological site near the Red Sea. Ancient Egyptians left their old boats in caves along the coast, but as the centuries passed the caves collapsed, making it impossible for archeologists to reach the sea vessels. One of Choset’s snakebots slipped through the rubble and sent back pictures for the researchers to analyze.
And are you ready for “snakebots on a plane”? It’s no science fiction spoof: Choset is currently working on a project with Boeing to develop snakebots that could work in manufacturing situations, applying paints and other coatings inside tight spaces, such as tanks. “Snake robots have tons of applications,” he says. “It’s the future of assembly.”
—Meghan Holohan is a Pittsburgh-based freelance writer and a frequent contributor to The Link. Her work also appears at NBCNews.com.
Meghan Holohan | thelink [atsymbol] cs.cmu.edu