Robots That Grow by Eating Other Robots is Not a Fantasy, Just a New Frontier in Engineering

Columbia University’s latest engineering project is straight out of a sci-fi novel, but it’s based on a simple idea: what if robots could grow, heal and adapt by absorbing parts from other robots? They call it “robot metabolism” and it flips traditional robotics on its head, from stiff, electricity-driven machines to robots that act like living organisms, using materials from their environment to evolve.

The project revolves around the Truss Link, a modular robot that looks like a high-tech version of a child’s magnetic building toy. Each Truss Link is a bar-shaped module with magnets at both ends, so it can expand, contract and connect to others. These units can roll across surfaces, link to form shapes and integrate new parts to grow or gain new abilities. Philippe Martin Wyder, lead researcher from Columbia Engineering and the University of Washington, sums it up: “True autonomy means robots must not only think for themselves but also physically sustain themselves. Just as biological life absorbs and integrates resources, these robots grow, adapt and repair using materials from their environment or other robots.”

This isn’t about building robot overlords – not yet, anyway. The Truss Links are simple, almost whimsical, looking like oversized Geomag toys. But their simplicity hides sophistication. In tests, the team showed these modules self-assembling into shapes like triangles and three-pointed stars, then transforming into complex 3D forms like tetrahedrons.

Hod Lipson, co-author and director of Columbia’s Creative Machines Lab, draws inspiration from biology. “Robot minds have advanced rapidly through machine learning, but robot bodies remain rigid, unadaptive and unrecyclable,” he says. “Biological bodies thrive on adaptation – lifeforms grow, heal and evolve. This is because biology is modular, reusing parts from other lifeforms.” The team wants to create robots that mirror this modularity, using materials from their surroundings or other machines to adapt in real time.

In disaster recovery, self-sustaining robots could rebuild from debris to navigate rubble or repair infrastructure. In space exploration, they could use local materials or parts from defunct probes to grow and thrive in harsh conditions. Wyder sees a bigger impact: “Robot metabolism provides a digital interface to the physical world, allowing AI to advance not just cognitively but physically – unlocking a new dimension of autonomy.”
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