American scientists have invented the first robot that is not only alive but can heal itself, raising as much concern as excitement over the rapidly accelerating rise of artificial intelligence (AI).
Researchers from the University of Vermont (UVM) and Tufts University in Massachusetts created the xenobot from amphibian stem cells. Stem cells are “blank” or unprogrammed cells that, under the right conditions, can regenerate and form new, different cell types.
The brand new life form was named after the African clawed frog Xenopus laevis that provided the biological material. These machines are tiny – less than a millimeter (0.04 inches) wide.
Back in 1966, in the movie Fantastic Voyage, a submarine with a human inside was shrunk to microscopic size and injected into a patient’s bloodstream to try to save his life. Today, the new xenobot is small enough to make its own fantastic voyage inside the human body.
But these minuscule automatons don’t need a submarine because they can walk and swim, go for weeks without a meal, work in cooperative groups, and heal themselves after being cut. They could potentially pick up and deliver a medicinal payload to a diseased body part.
Joshua Bongard, an award-winning computer scientist who specializes in evolutionary robotics, evolutionary computation and physical simulation at the University of Vermont, co-led the revolutionary research. This professor’s credentials are impressive:
“In 2007, [Bongard] was awarded a prestigious Microsoft Research New Faculty Fellowship and was named one of MIT Technology Review’s top 35 young innovators under 35. In 2010 he was awarded a Presidential Early Career Award for Scientists and Engineers (PECASE).”
According to Bongard, the world has never seen anything like a xenobot:
“These are novel living machines. They’re neither a traditional robot nor a known species of animal. It’s a new class of artifact: a living, programmable organism.”
The research team at UVM designed the living robot on the Deep Green supercomputer cluster at the university’s Advanced Computing Core which was then assembled and tested by Tufts biologists under lead author and doctoral student Sam Kriegman.
The computer programmers came up with an evolutionary algorithm that imitates natural selection by generating possible solutions and then repeatedly culling and further mutating the most promising ones to model thousands of most-likely-to-succeed theoretical designs for the new organisms:
“Attempting to achieve a task assigned by the scientists—like locomotion in one direction—the computer would, over and over, reassemble a few hundred simulated cells into myriad forms and body shapes. 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 algorithm churned out “thousands of random configurations of between 500 and 1,000 skin and heart cells and each one was tested in a virtual environment. Many were useless lumps. But those that showed potential—such as being able to move—were tweaked and used to seed the next generation. After running this process 100 times, the researchers built the best designs out of living cells.”
Co-leader Michael Levin directs the Center for Regenerative and Developmental Biology at Tufts and commented:
“We can imagine many useful applications of these living robots that other machines can’t do.”
Such applications include “searching out nasty compounds or radioactive contamination, gathering microplastic in the oceans, traveling in arteries to scrape out plaque,” said Levin.
Microsurgeon Douglas Blackiston worked with Levin to transform the computer models into laboratory lifeforms. The frog stem cells were divided into individual cells and left to incubate. The cells were then cut and rejoined using miniature forceps and an even smaller electrode under a microscope to create a near approximation of the computer-generated designs.
Skin stem cells were used to make relatively stationary biological structures. The ability to move forward unassisted was engineered from once-beating heart muscle cells.
Powered by embryonic energy stores, the xenobots moved in concert and explored their aquatic environment for up to weeks. They couldn’t survive being flipped over, however, much like an overturned turtle that can’t right itself and dies of starvation or exposure.
Further testing demonstrated that showed that groups of xenobots traveled in circles, spontaneously pushing pellets into a central location.
The scientists built some xenobots with a central hole to reduce drag. Simulations showed that the hole could serve as a pouch to transport an object. Bongard observed:
“It’s a step toward using computer-designed organisms for intelligent drug delivery.”
Robots are tools. In the right hands, they can help humanity thrive. But outside the ivory towers of academia, it doesn’t take much imagination to envision the dire consequences this technology could wreak upon us all if wielded by demented sociopaths.