It may sound like a nightmare, but luckily we have little to fear from these robots. In fact, we might benefit from their birth.

American researchers have developed robots that can reproduce themselves without humans interfering with it. A first.

In a petri dish

It’s a remarkable sight. Several Pac-Man-shaped robots roam around in a petri dish. But where Pac-Man feasts on globules and fruits, these robots collect cells. They collect these in their ‘mouth’, where the cells organize themselves in such a way that together they form a new robot that detaches itself from the mouth of the ‘mother robot’ after a few days, to then go on the hunt for cells themselves. and create new robots of their own. “They reproduce spontaneously,” said researcher Joshua Bongard.

Adventure

With the reproductive robots, Bongard and colleagues have taken a remarkable new step in an adventure that already made the newspaper last year. That’s when the researchers announced the creation of a ‘living robot’, which they had named Xenobot. A kind of biological machine, made up of living cells that the researchers had scraped from a frog embryo and organized on the instructions of a supercomputer in such a way that the cells together formed a robot that could move itself optimally. “These are new living machines,” Bongard said at the time. “They are not traditional robots (…) but a new type of object: a living, programmable organism.”

And building on that work, Bongard and colleagues now come up with Xenobots that can reproduce themselves. Again, a supercomputer was used. And cells of the frog Xenopus laevis. To be precise: embryonic cells that would normally grow into skin. “These cells are on the outside of a tadpole, keeping the pathogens out and redistributing the mucus,” said lead researcher Michael Levin. “But we put them in a new context.”

super computer

That context is dictated by a supercomputer, which has pondered how the cells should be organized to ensure that the resulting biological machine is not only capable of self-propelled but also self-reproducing. “It resulted in some strange designs after months of calculations, including one that was reminiscent of Pac-Man,” said researcher Sam Kriegman. The researchers then got to work and built these Pac-Man-like living robots. “And then those ‘parents’ built children, and those children built grandchildren, and they built great-grandchildren, who built great-great-grandchildren.”

Kinematic Replication

All these new generations were the result of ‘kinematic replication’, or propagation inspired by movement. “Almost all organisms reproduce by growing and then producing offspring,” the researchers write in their paper. “Some molecules also multiply, but they do so by moving, rather than growing. They find and combine building blocks to make copies of themselves. Here we show that clusters of cells—when released from the developing organism they were part of—can similarly find and combine single cells into cell clusters that look and move just like themselves.” In very concrete terms, researchers have thus succeeded – at the command of a supercomputer – in making a collection of cells that collect individual stem cells while moving, which together can grow into ‘young’ Xenobots. “These cells have the genome of a frog, but freed from the task of growing into tadpoles, they use their collective intelligence, their plasticity, to do something else amazing,” Levin says. “These are frog cells that replicate in a way that is very different from the way frogs do. As far as we know, no animal or plant reproduces in this way.”

The idea that “biological machines” are capable of propagating themselves indefinitely can be a little terrifying. But the researchers are happy to allay any concerns. The robots are only a millimeter in size, can easily be switched off and are stuck in their petri dishes. World domination is therefore a long way off. And the researchers are certainly not after that. Instead, they hope to do something good for humanity with the Xenobots. “If we know how to tell a collection of cells what we want it to do, we’re moving into regenerative medicine,” Levin said. “And that could be the solution to injuries, birth defects, cancer and aging. All those problems are there because we can’t accurately predict and control what groups of cells are going to build together. Xenobots are a new platform to learn more about that.”