Snakelike Robots May Fight Terror, Save Lives

Brian Handwerk
for National Geographic News
Updated March 11, 2003
Snakelike robots may soon fight terrorism, save lives, and make repairs on everything from battleship engines to the human body. Sound like science fiction? New research is bringing these incredible possibilities closer to reality. A leading researcher behind this endeavor is Howie Choset, a mechanical engineer and roboticist at Carnegie Mellon University in Pittsburgh, Pennsylvania. His goal is to perfect what he calls the "snakebot."

Choset's team is backed by a very interested party—the United States Navy's Office of Naval Research. The research branch has funded Choset's research since 1997, seeing promise in the application of snakebot technology to tasks as diverse as routine engine maintenance to diffusing bombs planted by terrorists.

Choset's work is on the cutting edge of robotics, but his idea is not an original one. Rather, Choset says he was first exposed to the notion serpentine robots while a graduate student at the California Institute of Technology, in Pasadena, through the work of his advisor, Joel Burdick, and Greg Chirikjian. "[They] really brought snake robots to the forefront to the United States. I fell in love with the idea."

Snakelike robots already exist in rudimentary forms. But Choset's creations push the envelope. Small and very strong by design, Choset's snakebots measure just five centimeters (two inches) in diameter. The use of beveled gears around their circumference, allows the serpentine robots many more degrees of movement than conventional robots—including the ability to move efficiently in three-dimensional space.

Choset's machines use complex mathematical algorithms that enable them to autonomously sense and respond to obstacles and variations they encounter while navigating across landscapes.

Such innovations mean that the snakebot may soon become a highly effective tool for difficult applications like the complicated and dangerous work of urban search and rescue.

Snakebots Could Aid Disaster Victims

"With their enhanced flexibility and 'reach' ability in convoluted environments, serpentine robots make sense for search and rescue," Choset said. "If you can locate a survivor, you've often saved his or her life. Just letting them know that help is on the way and pinpointing their location for rescuers can make the difference."

"Consider the collapsed World Trade Center [disaster of September 11, 2001]. The magnitude of the devastation exceeded the available resources of urban search and rescue specialists, dogs, and sensors," said Phillip Abraham, a physicist and science officer at the Office of Naval Research. "In other situations, the pancake collapse of large structures prevents rescue workers from entering buildings due to fear of further collapse. But the biggest problem is simply that both people and dogs are usually too big to enter voids."

Enter the snakebot, perfectly at home in the tangled, dangerous, and cramped environment that's dangerous or inaccessible to other search and rescue personnel.

"They would make a tremendous difference," said Robin Murphy, director of the Center for Robotic Assisted Search and Rescue at the University of South Florida in Tampa. "There are different types of rubble, so there is no perfect robot for search and rescue. Some existing robots, like those in use in Afghanistan, function well in open space, or can climb stairs. But these snakebots could get into very confined spaces without further disturbing unstable rubble. It would be very effective and it's very exciting."

Search and rescue operations are just potential application of the snakebot project. The serpentine robots could also be used to disarm explosives while minimizing the danger to humans.

"The snakebot might be able to penetrate inside a bomb or a landmine and disarm it while preventing a detonation," said Abraham. "Humans would be kept distant from the danger." The same application could be useful for disposing of unexploded bombs and landmines.

In the case of terrorist attacks or military applications, the robots could be used to assess the danger of potential chemical or biological threats. The devices could be equipped with sensors that detect various substances, from heat to chemicals or radioactivity. "You could send a snake robot into the area, have it conduct a search, and grasp a sample for analysis," Abraham explained. "The entire time you avoid human contact with the dangerous materials."

Repairs Possible for Ship Engines, and Eventually the Human Body

A non-glamorous role for the robots is no less important for the Navy. "I'm supported by the Navy to do engine inspection and hopefully engine repair," Choset said. "It's a sort of arthroscopic surgery on the engine of a sea vessel and it saves a lot of time. You don't have to take an engine apart, you could just put the snake device in and have it fix the problem."

"In many instances it could be useful to penetrate inaccessible spaces," Abraham added. "On a big ship there are lots of small spaces where humans don't have access. You may need to cut holes in the hull to get to a system that needs repair. A device like the snake could provide that kind of repair, such as laser welding, on the spot."

In this role, mechanical staff could use snakebots equipped with digital cameras to identify and illustrate specific problem areas, allowing machine and man to work in tandem to conduct engine inspections or locate fluid leaks.

In the future, similar robots might work on the most complex machine of all—the human body. "In the long run, the epic application for this technology is surgery," Choset explained. "It could enable us to perform better surgical operations without having to open up a person—but unless there is some kind of critical breakthrough that sort of thing won't happen for a while."

Major challenges still remain for Choset and his team. Presently, they are working to perfect mechanism design, sensor integration, and other technical issues for the snakebot.

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