This Caterpillar Robot Can Split Up and Reassemble Itself

image from video

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Ancient paper-folding and modern materials science were combined by engineers at Princeton and North Carolina State University to create a revolutionary soft robot with a steering system built directly into its body.

The researchers created the robot out of modular, cylindrical segments that can operate independently or join to form a longer unit, all contributing to the robot’s ability to move and steer. The system allows the robot to crawl forward and backward, pick up cargo, and assemble into longer formations.

Tuo Zhao, a postdoctoral researcher at Princeton, explained that the robot’s ability to assemble and split up allows the system to work as either a single robot or a swarm: “Each segment can be an individual unit, and they can communicate with each other and assemble on command… They can separate easily, and we use magnets to connect them.”

According to Techxplore, the researchers began by building their robot out of cylindrical segments and an origami form called a Kresling pattern, which allows each segment to twist into a flattened disk and expand back into a cylinder (as can be seen in the video clip). This twisting, expanding motion is the basis for the robot’s ability to crawl and change direction.

The next challenge, creating a mechanism to control the bending and folding motions used to drive and steer the robot, was solved by researchers at North Carolina State University. They used two materials (liquid crystal elastomer and polyimide) that shrink or expand differently when heated and combined them into thin strips. They then installed a thin stretchable heater along each fold, which was heated by an electrical current, making the different expansions of the two materials create a fold. The researchers can then precisely control the folding and bending to steer the robot.

The researchers concluded that while the current version of the robot has limited speed, they are working to increase the locomotion in later generations. They also intend to experiment with different shapes and patterns to improve both the speed and the steering.