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Watch these alienlike robots weave a bus-size fiberglass structure—all by themselves

If fiberglass tubes suddenly started to sprout out of the ground, you might think you had stumbled on some alien invasion. But such tubes are a real thing, woven by newly developed autonomous robots to create large structures such as bridges and temporary shelters—with minimal human input.

Each “Fiberbot” has a winding arm that pulls fiber from a tank on the ground, mixes the materials in a nozzle, and winds the wetted fiber around itself like a silkworm cocooning. Next, the robot turns on an ultraviolet light to cook the fiber into a hard tube. Then, it deflates its body and uses a tiny motor and wheels to inch itself up on top of the hardened fiber, where the process begins again.

The robots can tilt and use different winding patterns to vary the thickness and the direction of the tubes. As they build, the Fiberbots communicate with each other through a computer network to avoid running into each other or other obstacles. Together, they can calculate the most efficient way to build a given structure.

Over 12 hours, a team of 22 robots was able to build two treelike structures 4.5 meters tall (about the height of a double-decker bus), the researchers report today in Science Robotics. The researchers had intended the robots’ trees to meet in the middle to form a tentlike shelter, but found the machines actually overcorrected their paths to avoid bumping into each other. The structure was able to stand without damage for 7 months outside through high winds, rain, and snow during the fall and winter, until the researchers disassembled it.

The team says the technology could be used to build structures in remote environments with unknown terrain, like after an extreme weather event, because instructions on what to build can be beamed wirelessly to the robots, and they can adapt the blueprint around any obstacles that might crop up in their path. With further testing and refinement, the scientists say Fiberbots could be used on other planets. They do look like they would be right at home on a martian landscape.