Scientists inch closer to robots that can build almost anything, including other robots

Self-replicating robots are considered the holy grail of robotics. Imagine a future where robots can build almost anything, including copies of themselves, that then build other things. While this concept remains in science fiction, MIT scientists have developed an assembly system that moves us closer to such a future.

In new work published in the journal Nature Communications Engineering, researchers at MIT’s Center for Bits and Atoms (CBA) have built an assembly system that uses multiple robots that can move independently to build large objects using identical lightweight pieces called “voxels,” the 3D equivalent of pixels. Apart from these voxels, the system also uses actuators and grippers to build other robots.

While the new system is still far away from being fully autonomous, it makes important strides towards that goal. This includes the system’s ability to work out the complex tasks of deciding when it needs to build more robots or build a particular structure, and how big should these be. It can also organise swarms of different-sized robots to build a structure efficiently, without crashing into each other.

“The robot can not only assemble structures but also assemble other robots, even robots bigger than itself. The cuboctahedron-shaped voxels are structural, but also have PCB boards that can transmit power and data,” said Amira Abdel-Rahman, lead author of the paper, to indianexpress.com, over a video interaction. Abdel-Rahman is a doctoral student at CBA. A cuboctahedron is a polyhedron with eight triangular faces and six square faces.

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This work builds on years of CBA studies, including research into using such identical pieces to build objects like deformable aeroplane wings and functional racing cars. The robots in the latest study consist of strings of approximately three-inch-long cuboctahedron-shaped voxels attached end-to-end using magnetic connections.

Previous such systems have already demonstrated that they can use this principle to build large structures until they reach a certain size in relation to the robots, meaning it would require a larger robot for construction. But at this point, the robots of the new system will decide it's time to build a larger version of themselves, so that they can build the structure more efficiently.

“The system has to make choices every step of the way. It can either build a structure, or build another robot, or a larger robot. It can build recursively and could ‘multiply’ into a hierarchical robot system that can build much larger structures,” said Amira Abdel-Rahman.

© Provided by The Indian Express assembly robots The new study shows that the assembler robots and the structures they build can be made out of the same units. (Image credit; MIT)

Applications of self-replicating robots

One of the most tantalizing potential applications of this technology is space exploration—autonomous robots that can build large-scale solar power, communications and habitat systems to Mars. The ability to autonomously assemble such structures, instead of pre-assembling and sending them, will be crucial to sustainable deep space exploration.

“We can build almost anything with these cuboctahedron-shaped voxels. CBA is working on building cars with Toyota, aircraft with Airbus, and even ships with their partnership with Oldendorff,” added Abdel-Rehman.

The cuboctahedron structures used in the current version of the system are made from injection moulded plastic, but can be switched out for voxels of other sizes and compositions. Currently, CBA researchers are working on building voxels out of more sustainable biocomposites. Apart from that, CBA is also working on improving the connective mechanism between the voxels, the actuators and other mechanical components for better performance.