Meet the Living Machines - Xenobots
Imagine building a living organism from individual cells; once this organism is built it can move, be programmed and do several assigned tasks all without being controlled. After it runs out of food it dies and is fully biodegradable. Now imagine if this organism was designed by a computer algorithm. This breakthrough, by a team of scientists at the University of Vermont, was to create something completely new. It is the world's first living machine designed from the ground up. What they have created is “neither a traditional robot nor unknown species of animal. It is a new class of artifact, a living, programmable organism.
The researchers repurposed living cells scraped from frog embryos and assembled them into entirely new life forms. The original stem cells came from an African clawed frog known by the Latin name Xenopus laevis.After being harvested the stem cells were then separated into single cells and left to incubate. The cells were cut and joined together under a microscope. The resulting Assembly of living cells has been dubbed as Xenobot, and measuring just 0.04 inches or one millimeter wide these robots can move independently and collectively and survive for weeks at a time.
The new creatures were designed by a supercomputer at the University of Vermont and then assembled and tested by biologists at Tufts University. The DeepGreen supercomputer cluster (exceeds petaflop speed) at the University of Vermont ran for months at a time. This computer was custom designed allowing for cutting-edge AI. It used an evolutionary algorithm to create thousands of candidate designs for the new life-forms.
The scientists determined a desired task. In this case the task was movement. So the algorithm would create designs intended to produce the outcome of movement. The computer would assemble a few hundred simulated heart and skin cells into different body forms. The behavior of these cells was governed by constraints and parameters, e.g. the maximum muscle power of a frog heart cell, with these parameters as its guide the algorithm iterated the life-form designs. The more successful simulated organisms were allowed to reproduce inside the algorithm while the failed designs were thrown away. After a hundred independent runs of the algorithm the most promising designs were selected for testing and then later brought to life.
There is no external control from a remote control or bioelectricity and the Xenobot is an autonomous agent. As the muscles contracted, they worked to provide an ordered forward motion as simulated and predicted by the computers design. The contractions of the heart muscles were the mechanisms for motion. The skin cells on the other hand behaved as a scaffolding to hold everything together. The organisms managed to survive in their watery environment for weeks. They were powered by stored energy in the form of proteins. When the Xenobot’s environment was scattered with particles they spontaneously worked together moving in a circular motion to push the particles into one spot.
These living robots can be used for searching out unwanted compounds or radioactive contamination, gathering micro plastics in the oceans, traveling in arteries to scrape out plaque, carry medicine to a specific area inside of a patient, etc. The robots also have the benefit of healing themselves after being cut which is not possible with typical machines. Xenobots are also fully biodegradable. When they are done with their job, all that remains is just dead skin cells.
People are obviously going to be split on this issue blurring the lines between robots and living organisms. Debates around the implications of a rapid technological advancement in ever more complex biological manipulations are bound to happen. If Humanity is going to survive in the future, we need to better understand how complex biological properties somehow emerge from simple rules. A first step towards doing that is to explore how living systems decide what an overall behavior should be and how we could manipulate the species to get the behaviors we want. It is surprising to think that if left aligned to their natural development, the stem cells taken from the embryonic frogs would have turned into skin and heart tissue within living breathing animals, instead of configurations designed by a computer algorithm constructed by humans. And those cells were assembled into something completely new; a living programmable robot. Although the current states of Xenobots is relatively harmless, there is the potential for future work to incorporate a nervous system and countless other applications. As this field of research grows regulations and ethics guidelines will need to be seriously considered. This is an immense responsibility for humans to have and one of the biggest questions to if this should be done or not; and do the benefits outweigh the risks. At this stage it is impossible to know, though we should be cautious in how we proceed. Unintended Biological consequences are a matter of serious concern, nevertheless, the correct use of such technology to clean up our oceans or other such applications could be a game changer.
Research Paper : https://www.pnas.org/content/117/4/1853