Super Computer Produces Biological Robots
At the beginning of this year scientists at the University of Vermont programmed a supercomputer to create an anatomical blueprint for a computer designed organism called a xenobot.
Biologists at Tufts University then incubated the stem cells scraped from the embryos of African frogs, built entirely from green frog skin and red heart muscle, and cut them to mimic the design created by the computer.
They were then assembled into body forms not seen in nature, entirely new life forms in fact, and on testing the cells worked together and the robots became independently mobile.
The plan is to use these xenobots, that’re programmed to move towards a target, in delivering drugs to a specific area inside a patient’s body as well as in environmental clean-up operations.
Furthermore, these xenobots have the ability to heal after being cut or damaged and are biodegradable when they die.
Billed as “living machines” “neither a traditional robot nor a known species of animal but a new class of artifact: a living, programmable organism” by the co-leader of the research team, Joshua Bongard.
Director of the Center for Regenerative and Developmental Biology at Tufts, Michael Levin, said, “We can imagine many useful applications of these living robots that other machines can’t do, like searching out nasty compounds or radioactive contamination, gathering micro plastic in the oceans, or traveling in arteries to scrape out plaque.”
Manipulating organisms for human benefit are nothing new, consider Genetic Modified Organisms in Agriculture and now gene editing in humans and animals, think ‘designer babies’ here, both practices are widespread though controversial, but with this new research completely biological machines are constructed from the ground up, for the first time ever.
It Begins
With months of processing time on the Deep Green supercomputer cluster at UVM’s Vermont Advanced Computing Core, the team, including lead author and doctoral student Sam Kriegman, used an evolutionary algorithm to create thousands of candidate designs for the new life-forms.
As the programs ran, driven by basic rules about the biophysics of what single frog skin and cardiac cells can do, the more successful simulated organisms were kept and refined, while failed designs were tossed out.
After a hundred independent runs of the algorithm, the most promising designs were selected for testing.
The Biology Part
Later in the lab the skin cells formed a passive architecture, while the once-random contractions of heart muscle cells were put to work creating ordered forward motion as guided by the computer’s design, and aided by spontaneous self-organizing patterns, allowing the robots to move on their own.
These reconfigurable organisms were shown to be able move in a coherent fashion, and explore their watery environment for days or weeks, powered by embryonic energy stores.
Turned over, however, they failed, like beetles flipped on their backs.
Later tests showed that groups of xenobots would move around in circles, pushing pellets into a central location, spontaneously and collectively.
Others were built with a hole through the center to reduce drag.
In simulated versions of these, the scientists were able to re-purpose this hole as a pouch to successfully carry an object.
“It’s a step toward using computer-designed organisms for intelligent drug delivery,” says Bongard, a professor in UVM’s Department of Computer Science and Complex Systems Center.
In the experiments scientists cut the xenobots and this is what happened.
“We sliced the robot almost in half and it stitches itself back up and keeps going,” says Bongard. “And this is something you can’t do with typical machines.”
The results of this new research were published on January 13 in the National Academy of Sciences.
