What happens when you take cells from frog embryos and grow them into new organisms that were “evolved” by algorithms? You get something that researchers are calling the world’s first living machine.
Though the original stem cells came from frogs the African clawed frog, Xenopus laevis these so-called xenobots don’t resemble any known amphibians. The tiny blobs measure only 0.04 inches (1 millimeter) wide and are made of living tissue that biologists assembled into bodies designed by computer models, according to a new study.
Scientists recently reported that these mobile organisms can move independently and collectively, can self-heal wounds and survive for weeks at a time, and could potentially be used to transport medicines inside a patient’s body.
Study co-author Joshua Bongard, a computer scientist and robotics expert at the University of Vermont, said in a statement that they are neither a traditional robot nor a known species of animal. It is a new class of artifact: a living, programmable organism.
Study author Sam Kriegman, a doctoral candidate studying evolutionary robotics in the University of Vermont’s Department of Computer Science, in Burlington said Algorithms shaped the evolution of the xenobots. They grew from skin and heart stem cells into tissue clumps of several hundred cells that moved in pulses generated by heart muscle tissue.
Kriegman told that There are no external control from a remote control or bio electricity. This is an autonomous agent. It is almost like a windup toy.
Biologists fed computer constraints for the autonomous xenobots, such as the maximum muscle power of their tissues, and how they might move through a watery environment. Then, the algorithm produced generations of the tiny organisms. The best-performing bots would “reproduce” inside the algorithm. And just as evolution works in the natural world, the least successful forms would be deleted by the computer program.
Kriegman said “Eventually, it was able to give us designs that actually were transferable to real cells. That was a breakthrough,”
The study authors then brought these designs to life, piecing stem cells together to form self-powered 3D shapes designed by the evolution algorithm. Skin cells held the xenobots together, and the beating of heart tissue in specific parts of their “bodies” propelled the ‘bots through water in a petri dish for days, and even weeks at a stretch, without needing additional nutrients, according to the study. The ‘bots were even able to repair significant damage.
He said “We cut the living robot almost in half, and its cells automatically zippered its body back up”.
Study co-author Michael Levin, director of the Center for Regenerative and Developmental Biology at Tufts University in Massachusetts said “we can imagine many useful applications of these living robots that other machines can’t do”.
These might include targeting toxic spills or radioactive contamination, collecting marine microplastics or even excavating plaque from human arteries, Levin said in a statement.
Creations that blur the line between robots and living organisms are popular subjects in science fiction; think of the killer machines in the “Terminator” movies or the replicants from the world of “Blade Runner.”
The prospect of so-called living robots and using technology to create living organisms understandably raises concerns for some.
Levin said “when we start to mess around with complex systems that we don’t understand, we’re going to get unintended consequences.”
Nevertheless, building on simple organic forms like the xenobots could also lead to beneficial discoveries.
He further said “If humanity is going to survive into the future, we need to better understand how complex properties, somehow, emerge from simple rules”.