The first image that comes to mind for most people when they hear the word “robot” is of a metal machine full of wires and circuitry. While synthetic robots are easy to manufacture and program, they can also have harmful environmental or health consequences. To get around these problems, scientists have begun to perform research with Xenobots, which are made entirely of living tissue but can still be manipulated to perform various functions. This innovation blurs the lines between technology and biology, providing unprecedented potential for future applications of robotics.
Artificial Architects
Inspired by the prospect of creating completely biological robots, scientists from the University of Vermont, Tufts University, and Harvard University began using artificial intelligence (AI) to make a practical design. This machine learning algorithm has two basic units to work with, a passive cell that serves a structural purpose and a contractile cell that allows for movement. It arranges these cells in various different ways and simulates the resulting design in a 3D space where their functionality can be tested. The final design arranged the cells to look like the letter ‘C’, which is useful for both motility and object manipulation.
Miniature Assembly Line
After the design was complete, scientists began creating the robots. They used stem cells from the embryos of African clawed frogs, Xenopus laevis, from which the name ‘Xenobot’ is derived. Stem cells are undifferentiated cells that have the potential to develop in many different ways, so extracting them allows scientists to arrange them into robots instead of frogs. Skin cells play a passive, structural role, while cardiac muscle cells act as contractile cells, pushing the Xenobot around as they pulse like a heart. The manufacturing process is a difficult one, requiring precise work at a microscopic scale, but the final results behaved similarly to the simulation and were made entirely of biological material.
"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."
-Joshua Bongard, lead researcher
Avant-garde Workforce
Xenobots have the potential to perform a variety of functions more safely and efficiently than regular robots. They can survive for weeks without needing additional nutrients, repair themselves when damaged, and even reproduce, making identical Xenobots. In ecology, they can be used to clean waste or collect microplastics from the ocean without polluting it because they would simply decompose as they die. Their applications in healthcare are also promising, as they can be used to deliver medicine throughout the body or to clean built up plaque in blood vessels. Even if they are just used for research, they can help us understand how to manipulate biological cells, possibly paving the way to reprogramming cancerous tumours or regenerating body parts. Because this tech is so new, there are still so many possibilities to explore.
Unconventional Quandaries
As exciting as this technology is, it raises numerous ethical questions. The idea of scientists rearranging living cells into a strange, controllable robot-creature can cause some to worry, and the fact that these robots are designed by AI further agitates people’s anxiety. However, the researchers are adamant that there is no cause for concern. Xenobots replicate by gathering loose cells, but they do not have reproductive structures, so uncontrolled evolution would not be an issue. As for the AI, the researchers are making sure a human being verifies each design before it is actually created. Currently, their main concern is unintended side-effects, but there is still a long road to go before Xenobots can be deployed to perform tasks outside the lab.
Research into Xenobots is still in its earliest stages but it stands out from other research in cell biology and robotics. Although they are technically organisms, the fact that they are designed by an AI and engineered in a lab puts them in a difficult grey area that science has not yet explored. They are made of frog cells and they have frog genes, but they cannot be called frogs. Xenobots offer a glimpse into a future where nature and technology are interconnected and inseparable.
References
https://www.cnn.com/2020/01/13/us/living-robot-stem-cells-intl-hnk-scli-scn/index.html
https://www.cnn.com/2021/11/29/americas/xenobots-self-replicating-robots-scn/index.html
