Movie audiences were wowed by the special effects in the 1991 film Terminator 2: Judgment Day, when a human-like robot changed its form and squeezed through small holes.
The Defense Advanced Research Projects Agency now wants to take a small step toward making science fiction a reality with a robot that can perform the same shape-shifting functions.
Such a robot would need to be soft, flexible and highly resilient, said Mitchell Zakin, a program manager at DARPA. He’s calling the concept the “ChemBot” because its outer layer will have to be made of a pliable skin-like substance rather than of inflexible hard metal.
“During military operations it can be important to gain covert access to denied or hostile space,” said Zakin. A new class of soft, flexible, mobile objects that “can identify and maneuver through openings smaller than their dimensions to perform various tasks will be quite valuable to many missions,” he added.
DARPA and the Army Research Laboratory awarded a $3.3 million contract to iRobot Corp. to develop the technology.
DARPA is looking to the animal world for inspiration. Cats can squeeze their bodies through small openings by narrowing their shoulder blades and chest muscles. Rodents are infamous for invading homes through holes and cracks that are even smaller than their bodies.
The current generation of ground robots that are used for surveillance employ wheels or tracks for mobility. That limits where they can go, and makes them less stealthy.
Other projects are pursuing the same goal. The Army Research Laboratory in April awarded a $37 million contract to BAE Systems to develop insect-like robots to help soldiers conduct urban surveillance. Carnegie Mellon Robotics Institute students are developing a “snake-bot” that can also move through small openings, climb and swim while carrying a camera on its tip.
The ChemBots will have to make it through “openings barely larger than their largest ‘hard’ component,” said Zakin. The “hard” component will be the core which contains the necessities for a robot to function. A ChemBot will have to travel a specified distance, push through an opening smaller than itself, reconstitute its shape and then perform a function using an embedded payload, most likely a camera.
DARPA officials have noted that having such a revolutionary robot will be beneficial in any situation that involves searching in a cluttered area that is too small for a soldier to enter.
“We’re looking at a range of technology,” said Chris Jones, research program manager for iRobot. “To build this robot you need power, sensors, computing … You need to be able to sense, you need control, you need communication and all of these pieces need to be soft and flexible.”
Today’s robots are assembled with hard materials that make physical transformation impossible. A different scientific approach must be taken, said one expert.
“[The robot] must have outstanding actuators,” said Delbert Tesar, director of the University of Texas Robotics Research Group. These are “like muscles in the human body, the better the actuators the more likely the robot can reconfigure.” The robot must also have high quality sensors for tight configuration when squeezing into spaces and to back out of dead ends.
The better the sensors and actuators are on the robot, the better it can feel its surroundings and determine what size it should be to squeeze into an area, he said.
In the first phase of the project, researchers will attempt to construct a prototype that is approximately the size of a soda can that can “travel five meters at a speed of .25 meters per minute, decrease to a 10th of its size, squeeze through a one centimeter opening and reform to its original size and shape in 15 seconds, said DARPA officials.
iRobot is still unsure how it will create such durable and pliable material.
In a study conducted by the National Institute of Advanced Industrial Science and Technology in 2002, researchers determined that locomotion in self-configured, three-dimensional robotic structures presented a difficult problem. Robots that are created to reshape themselves had issues moving from one place to the next. The researchers discovered that it was fairly easy to create a robot capable of morphing, but found mobility the greatest challenge because of the many modular configurations necessary to both reconstruct itself and to move.
DARPA and iRobot have assembled a team of researchers from Tufts University, University of Chicago, Harvard, Massachusetts Institute of Technology and Boston Dynamics to tackle the problem. The team will try to overcome basic issues regarding robotics technology before tackling problems such as obstacle avoidance and whether the robot will be remotely controlled or automatically maneuvered.
DARPA has not announced a completion date for the project.