In early 2020 a team of computer scientists from the University of Vermont and biologists at Tufts University built “biological robots” for the first time. A little more than a year later, the same team discovered a new way to build the so-called xenobots. A way that involves much less direct physical manipulation. Now, the researchers say they’ve figured out how to make the “xenobots” reproduce all on their own.

DesignTAXI reported on the new iteration of the researchers’ xenobots. The team outlined the findings in a paper recently published in the journal PNAS. For this experiment, the researchers, who are aiming not only to explore the origins of multicellular life, but also build organic tools that could say, eat up plastic in the ocean, showed that the living bots are able to reproduce autonomously. Specifically by collecting cells around them and using those cells to build “offspring” of sorts.

In the video above the researchers show how the xenobots, which consist of embryonic frog cells, are able find single cells around them. Then, subsequently gather hundreds of the cells together and assemble “baby” xenobots inside themselves. In a normal situation, these cells would’ve sat outside of a tadpole fighting off pathogens and redistributing mucus before eventually becoming skin cells. But here, the researchers capitalized on the cells’ tendency to combine with each other to make the reproducing bots.

Xenobot cellular robots collecting cells with their Pac-Man mouths in order to create baby xenobots.
University of Vermont

“With the right design — [the xenobots] will spontaneously self-replicate,” Joshua Bongard, a computer scientist and robotics expert at the University of Vermont who co-led the new study, said in a press release. “These are frog cells replicating in a way that is very different from how frogs do it. No animal or plant known to science replicates in this way,” Sam Kriegman, the lead author of the study added. The researchers even deployed an “evolutionary” AI algorithm to test billions of body shapes before coming up with one that worked well for reproduction. Incidentally, it kind of looks, and acts, like a Pac-Man.

The xenobots (a portmanteau of the frog species providing the cells, Xenopus laevis, and “robots”) themselves look like globular popcorn. And indeed, they seem like little, mindless robots. A lot like something you’d see in an automated warehouse. Along with reproducing, the xenobots can also assemble “communities” of sorts. And even exchange environmental information with chemical signals.

University of Vermont

The team says it’s currently investigating ways to make “swarms” of xenobots. These “swarms” would particularly be for applications in biomedicine and environmental preservation. Which, while amazing, sounds even creepier now that we know these little living bots can reproduce on their own. Although it’s still miraculous to realize that frog DNA is happy to turn cells into robots if it can’t make frogs with them.

Originally published on April 2, 2021.