Meet the Xenobots: entirely new lifeforms that were created in the lab in 2020. Using stem-cells from frogs, scientists created the world’s first living, self-healing robots. They are less than a millimetre wide — which makes them small enough to travel inside the human body. They can walk, swim, work in groups and survive without food for weeks. And now they have started to reproduce!
How was this done? Most cells in living things are specialized and know their function. But there are also un-specialized stem-cells that have the ability to develop into different types of cells. Researchers took living stem-cells from the skin and heart muscle of frogs, let them incubate and then cut and reshaped them into different forms designed by a computer. They were equipped with their own food source (lipids and proteins) so they can live for about 7 days. However, they do not have a brain, cannot reproduce and exhibit only functional behavior.
These new lifeforms can help us do a lot of things such as clean up radioactive waste, collect micro-plastics in oceans, but most importantly they can serve as medicine delivery mechanisms or even to clean up plaque from arteries because metal micro-bots (that are currently being used) can be harmful to the human body, and they can help us learn more about cell biology.
AI methods automatically design diverse candidate lifeforms in simulation (top row) to perform some desired function, and transferable designs are then created using a cell-based construction toolkit to realize living systems (bottom row) with the predicted behaviors.(Credit: https://cdorgs.github.io/)
So how did they start to reproduce?
While originally the researchers used a combination of heart and skin cells to have them move around in their Petri dishes, they subsequently used skin cells with hair-like structures called cilia. These cilia allow the xenobots to swim around in their dishes.
Then they researchers wanted to see if the xenobots could push things around and gave them light dye particles and then tiny glass beads. The xenobots could push both of these around! They were then given more and more things to move around including the cells from which the xenobots themselves were composed.
And this was the game-changer! The xenobots began to push the cells into piles. These piles of frog cells began to stick together and after a few days, the scientists observed that hairs (or cilia just like the xonobots) had started to emerge on their surface. Some of these then started to move around. Clearly the xenobots were reproducing!
The researchers then instructed the AI they had used to make the xenobots evolve into better versions. This opens them up to a lot more functions including environmental clean-up, vaccine delivery and even technologies that can put out forest fires.
However, it must be understood that the xenobots require very specific conditions to be able to self-replicate in this way. If they do not have access to free-floating cells they would not be able to replicate and would in-fact die in a few days, as was the initial intention.
(Cancer killing immune cells and artificial life-forms)
The researchers do not know if the xenobots are actually cooperating with each other. Also, can they be made using human cells? This is a question that the researchers are looking at answering in the future.
For the moment, they are studying the ones that they already have to see what other future potential.
Sometimes, science is more fascinating than science fiction!
Website for Computer Generated Organisms (XENOBOTS)
Source code for the Computer Generated Organisms (XENOBOTS)
