First robots from living cells they have been constructed by scientists, in a development that makes us question even our existence.

Its creators have called them xenobots, and they are small droplets of sub-millimeter size that have between 500 and 1,000 cells capable of moving through a Petri dish.

A quadruped organism made of 650-750 microns in diameter. Credit: Sam Kriegman, UVM

Biological robots can even organize themselves and even transport tiny payloads. They are different from any living organism or other organ that has developed so far.

Joshua Bongard, computer scientist and robotist of the University of Vermonthe said in a release:

These are novel living machines. They are not a traditional robot or a known species of animals. It is a new class of artifacts: a living and programmable organism. ”

Xenobots: biological robots

Its design required the use of a supercomputer and an advanced algorithm that gathered virtually hundreds of heart and frog skin cells in various configurations (similar to LEGO bricks), and performed several simulations of the results.

Credit: Kriegman et al., PNAS, 2019

Based on this, the scientists assigned a desired result, such as locomotion, and the algorithm was responsible for creating designs in order to test these results.

Thousands of configurations were designed, and different levels of success were achieved. The researchers ruled out the less successful configurations, maintaining the best and refining them, until they were as good as expected.

Later, the team chose the most promising designs and built the robots from harvested cells from african frogs embryonic (Xenopus laevis). For this, microscopic tweezers and an electrode were used in a completely thorough work.

Xenobots: successful configurations

At the end, the different built configurations managed to move, as did the simulations.

The researchers determined that skin cells are used as a kind of scaffolding that holds everything together, and heart muscle cells are used to boost xenobots.

Credit: Kriegman et al., PNAS, 2019

The micromachines managed to move in an aqueous medium for a week without giving them additional nutrients. They were fed using their own “pre-charged” energy reserves in the form of lipids and proteins.

One of the designs was added a hole in the center to reduce resistance. In addition, this hole was useful for transporting objects. The researchers improved the design and incorporated a bag that allows transporting objects in the simulation.

However, in the real world, the xenobots also managed to move objects in a circular environment, pushing particles towards a certain point.

New ways of life

Researchers indicate that it is a fascinating project, and that development can provide invaluable information on how cells communicate and work together.

Michael Levin, biologist of the Tufts Universityhe said in a release:

You look at the cells with which we have been building our xenobots and, genomically, they are frogs. It’s 100 percent frog DNA, but these are not frogs. Then you ask, well, what else are these cells capable of building?

As we have shown, these frog cells can be induced to create interesting living forms that are completely different from what their predetermined anatomy would be. ”

Although researchers describe them as “living beings.” Some disagree with that idea. However, it should be borne in mind that these xenobots cannot evolve on their own, they do not have reproductive organs and cannot multiply.

By running out of nutrients, the xenobots bind into a small group of dead cells, that is, they are biodegradable, giving them an advantage over plastic and metal composite robots.

Although currently the xenobots are totally harmless, in the future they could incorporate nervous system cells, which could make them possible biological weapons. In view of this, it would be necessary to apply and comply with regulatory and ethical guidelines.

However, scientists believe that there may be many useful applications that xenobots can make and that other machines cannot. For example: search for radioactive compounds, capture microplastics in the oceans, be introduced into the arteries to scrape the plaque, etc.

The research has been published in Proceedings of the National Academy of Sciences and the team has made available its source code in Github.

Source: The University of Vermont