Xenobots — How to create living machines

The future of robots might be softer than you think

When we imagine the future of robots we usually think of machines made out of metal or hard plastic. This types of robots will definitely be part of our future, with application in engineering, space exploration and automation. But another type of robots is also on the horizons : Xenobots.

Xenobots are names after an African frog Xenopus laevis. Scientist are created this synthetic organisms from frog embryos. A new study recently published in Science Robotics shows what progress we made compared to the last version of these Xenobots. These new ones are stronger and able to do way more things. But let’s first have a look at how they are made.

How do you create a Xenobot ?

Xenobots are made of only 2 constituents : skin cells and heart muscle cells. Both of these are created with stem cells harvested from embryos of our cute little frog. The skin cells are the support on which the entity relies. And the muscle cell is the motor that will allow it to move around by expanding and retracting.

Now the question is : how do you arrange these cells to have something that work ? (or rather, that moves). To do this, the scientist used a trial and error process, also names evolutionary algorithm. That way they simulated thausands of configuration and only kept the one that would work for the task intended.

Said like that it seems pretty easy but it still required a lot of computing power to process.

But of course you then need to build this arrangement of cells. And if done by hand with specialised tools, that would be very long and not scalable. Therefore the team used a bottom-up approach where the cells would basically self-organize into the living form that they wanted.

With this technique, they were able to create Xenobots composed of thousands of cells. And these Xenobots could move thanks to the cilia that covered the organism.

Okay, we now know how these Xenobots are made, the next question is : what can they be used for ?

Why has this technology so much potential ?

The authors admit it, right now it’s unclear what will be the best application of this kind of technology. But they still show and test some propositions. For example, they can “clean” some environment. Indeed, in an experiment, they saw that groups of Xenobots could spontaneously start to aggregate particles. This being the result of their natural movement. We can imagine this being used to clean some hard to reach environments.

Also, these robots are completely biodegradable, therefore not impacting the environment after their lifespan of our 10 days ends. Plus, they can heal themselves. The researchers tries to damage the agglomerate of cells by cutting half of the diameter of the individual. Between 5 and 15 minutes after the cut, the Xenobot repaired himself entirely. This shows how powerful it is to use the already existing life canvas : it knows how to heal and take care of itself.

Even more impressive, in another experiment, the team injected a specific RNA in the individual. This RNA was caused the cells to produce a specific fluorescent protein when exposed to a particular light source. This way, they could know if their Xenobots was exposed to a particular light source. It might not sound impressive, but it shows that it’s possible to retrieve a record of what the Xenobot experienced, which is a huge progress.

What is next ?

This studied showed that it’s possible to use the natural process of cells self organization to create a Xenobot specifically for a precise task. And these bots can work together to perform actions. This is just the beginning. We might soon see swarm of biodegradable robots cleaning our rivers or oceans. They might also help delivering a specific medication in your body, with the certainty that in a few days they will be entirely processed.

The main questions will actually be the ethical ones. Are we considering all the risks properly ? Using nature to create our own machines is not something we should take like a mundane task. If something goes wrong, it could be very dangerous.

Science will probably still go forward, so we should address these questions as soon as possible to benefit from this technology as soon as possible. Finally a soft technology in this concrete and metal world.