In a potential breakthrough for regenerative medicine, scientists have created the first-ever living robots that can reproduce.
The millimetre-sized living machines, called Xenobots 3.0, are neither traditional robots nor a species of animal, but living, programmable organisms.
Made from frog cells, the computer-designed organisms, created by a US team, gather single cells inside a Pac-Man-shaped ‘mouth’ and release ‘babies’ that look and move like their parents.
Self-replicating living bio-robots could enable more direct, personalised drug treatment for traumatic injury, birth defects, cancer, ageing and more.
Xenobots are the work of biologists and computer scientists at Tufts University and the University of Vermont (UVM), who have detailed their creation in a new study.
Xenobots 3.0 follow the original Xenobots, reported in 2020 as the first living robots, and Xenobots 2.0, which can self-propel using hair-like ‘legs’ called cilia and have the ability to keep memories.
‘We found Xenobots that walk. We found Xenobots that swim. And now, in this study, we’ve found Xenobots that kinematically replicate,’ said study author Joshua Bongard, a computer scientist and robotics expert at the University of Vermont.
‘We’ve discovered that there is this previously unknown space within organisms, or living systems, and it’s a vast space.’
Xenobots will help develop computer-designed organisms for intelligent drug delivery, according to the team.
‘If we knew how to tell collections of cells to do what we wanted them to do, ultimately, that’s regenerative medicine – that’s the solution to traumatic injury, birth defects, cancer, and aging,’ said Michael Levin at Tufts University.
‘All of these different problems are here because we don’t know how to predict and control what groups of cells are going to build. Xenobots are a new platform for teaching us.’
In 2020, the scientists revealed they’d hand-built the original computer-designed Xenobots, adapted from stem cells of Xenopus laevis, a species of frog found in parts of Africa.
Stem cells – which can turn into any tissue or organ – were harvested from the embryos of the frogs and left to incubate.
Then, with tiny forceps and an even smaller electrode, a microsurgeon cut and joined the single cells under a microscope into the shapes specified by a computer.
Assembled into body forms never seen in nature, the cells began to work together, powered by embryonic energy stores.
At the time, they showed that the bots were programmed to perform a range of tasks including delivering medicine directly to a point in the body.
This new generation – Xenobots 3.0 – uses stem cells from the same frog species.