Henry Ford’s assembly line changed the entire concept of manufacturing. With it, his factory was able to produce cars faster, cheaper, and more consistently than anyone else. In the hundred years since, the technique has been greatly enhanced—robots can now do most of the manual labor, for example. The next great frontier of manufacturing is approaching, however, and it promises to have a societal impact at least as large as Ford’s. The technology is molecular manufacturing—manufacturing from the “bottom up” as opposed to the “top down.” It involves assembling objects starting at the molecular scale, resulting in an atomically precise product. While there are huge potential benefits to this technology, which is quickly becoming a reality, there are large potential dangers as well. This paper will give a brief overview of molecular manufacturing and then discuss some of the risks and precautions that should be taken to deal with them.

The idea of molecular manufacturing can be traced back to a famous lecture given in 1959 by Nobel Prize winner Richard Feynman. In this lecture, titled “There’s Plenty of Room at the Bottom,” Feynman spoke of “a billion tiny factories” all working together, and touched on the absolute perfection that could be attained at the atomic scale (1). “If we go down far enough,” he said, “all of our devices can be mass produced so that they are absolutely perfect copies of one another.” He went on to say “I am not afraid to consider the final question as to whether, ultimately—in the great future—we can arrange the atoms the way we want; the very atoms, all the way down! What would happen if we could arrange the atoms one by one the way we want them?”

Forty years later, 35 xenon atoms were arranged to spell out “IBM” (2). In the 20 years since, further advancements have been made. Scientists are getting closer to being able to manipulate atoms in more complex ways than ever before. The xenon atoms, for example, were individually pulled into place one at a time on a nickel crystal at a temperature of 7 Kelvin. Obviously, this was a long way from being practical from a molecular manufacturing standpoint. In a paper published in Nature in 2000, scientists described the development of DNA-based “tweezers” with arms of only 7 nm (3). Team leader Dr. Yurke, winner of the 2001 Max Born Award, said in an interview with the BBC that these tweezers could help “lead to a test-tube based nanofabrication technology that assembles complex structures, such as circuits, through the orderly addition of molecules (4).”

Three-dimensional DNA crystalline structures. New York University chemists linked DNA double helices into triangles using single stranded sticky ends.

Three-dimensional DNA crystalline structures. New York University chemists linked DNA double helices into triangles using single stranded sticky ends.

DNA has also played a huge role in the laboratory of NYU professor Ned Seeman. From branched DNA, he produced a cube with each side containing only two turns of the double-helix (5). He and his team also built many other structures including a truncated octahedron and a “bipedal” strand of DNA that can “walk” along larger molecules (6). These tiny structures and machines could one day serve as the building blocks and assemblers for other, more complex nanomachines.

It is likely that as this technology develops, the rate at which advancements are made will increase dramatically. In their paper “Challenges and Pitfalls of Exponential Manufacturing,” published as a chapter of Nanoethics: The Ethical and Social Implications of Nanotechnology, Mike Treder and Chris Phoenix describe how the first tools that can easily position atoms can be used to make progressively better tools, which will in turn make even better tools (7). In a similar fashion, once a single “nanofactory” is produced, it can be used to make more, exponentially speeding up the process. For this reason, it is prudent to look at potential societal and ethical concerns of molecular manufacturing now, because we have no way of knowing how quickly development of this technology might accelerate. Treder and Phoenix say, for example, that if a nanofactory takes 24 hours to build a new nanofactory, and each newly produced nanofactory starts making new nanofactories immediately, the number produced within a month (230) is high enough that every household in the world would have one. Obviously, this situation is probably quite extreme, but nonetheless it is a powerful demonstration of the exponential nature of the situation.

The potential social impacts of this technology are huge. The potential benefits are mind-boggling. If used correctly, nanofactories could reduce hunger and disease dramatically, essentially eliminate pollution, and make advanced technology available around the globe. Simply by imputing raw materials, one could obtain highly nutritious food, vaccines, mosquito nets, or other materials vitally needed in poorer parts of the world. Scientists could develop new cures by designing molecules on computers and “printing” them in nanofactories. The possibility for good seems endless.

On the other hand, however, there are serious risks. Personal nanofactories could dramatically change our current economic system. For just the cost of raw materials and electricity one would be able to build anything, provided that one had the correct blueprint to feed into the machine. If the process were reasonably fast and cheaper than traditional manufacturing, it is reasonable to assume that many jobs would be lost. In all likelihood there would be many effects that cannot be predicted, and most of the predictions we make are likely to be far from the mark, but it is doubtless that there will be severe ramifications from the advent of this technology.

A molecular-scale fine-motion controller designed to move in precise, deliberate patterns on a small scale. The structure contains fewer than 3,000 atoms, but can execute 90 degree rotations at the atomic level.

A molecular-scale fine-motion controller designed to move in precise, deliberate patterns on a small scale. The structure contains fewer than 3,000 atoms, but can execute 90 degree rotations at the atomic level.

Treder and Phoenix suggest the possibility of an arms race (7). Whichever country develops nanofactory technology first would be placed in a position of immense power. They would be given a tremendous economic and military advantage over other countries, and might be inclined to keep that advantage by suppressing nanofactory development overseas. A sure way to do this would be by the threat of military intervention, and a nanofactory could potentially be the vehicle by which some of the most potent weapons ever designed are created. If the technology fell into the wrong hands, terrorist attacks or military coups could result. Another problem is known as the “gray goo” scenario, introduced by K. Eric Drexler in his book Engines of Creation (8). It posits a self-replicating nanobot, like a self-sustaining nanofactory for making more nanofactories, which can get all of its resources, including energy and raw materials, from the environment. If these are created and let loose, the theory goes, they could spread over the globe, consuming resources and multiplying at an exponential rate. This is known as ecophagy, and while there is some debate as to how likely it is to occur and how easily it could be stopped, it should be regarded as a potential problem.

Given that there are potentially enormous benefits but equally large risks associated with the development of molecular manufacturing and nanofactories, how ought we approach the problem? On one hand is the classic cost-benefit analysis. By estimating likelihoods and severities of the various risks and potential gains of the technology, we can decide if it is worth pursuing.  This strategy has some problems. For one, there are likely to be many outcomes that we cannot anticipate—just think about computers. In 1943, Tom Watson said “I think there is a world market for maybe five computers” (9). With such an untested technology, making predictions, let alone assigning probabilities to them, seems unfeasible. Another potential flaw with this method of thinking is its treatment of disaster scenarios. If we say that the elimination of the human species is the ultimate risk, and assign it a utility value of negative infinity, then any action which carries with it even the slightest chance of that outcome should be avoided. For example, before the first atomic bomb was tested, Edward Teller, one of the scientists who had worked on the Manhattan Project, co-authored a paper saying that an atomic bomb had the potential to “ignite the atmosphere” by fusing nitrogen nuclei (10). He said that this was unlikely but possible. In this case, though, it was decided that the potential risks were outweighed by the potential benefits, namely ending World War II. In a conventional cost-benefit analysis, even the slightest chance of annihilation, despite being extremely slight and contested by most scientists, would have been enough to keep the test from happening. Therefore, if there is a small, theoretical possibility of a life-ending catastrophe, the technology should not be pursued.

Another way of determining the best course of action in for this complex situation is the Precautionary Principle. It can take many formulations, but a common one, according to John Weckert and James Moor in their paper “The Precautionary Principle in Nanotechnology” is that “if action A has some possibility P of causing harmful effect E, then apply remedy R” (11). They clarify that A is normally a technological advancement of some kind, P cannot be merely a theoretical possibility, and that E should be a serious and irreversible harm. The Precautionary Principle might seem at first to be somewhat anti-development. After all, taking risks has been integral to many of mankind’s greatest achievements. We would never have landed a man on the moon if we had employed this principle. Regardless, it is worth serious consideration. Radical new technologies — and molecular manufacturing would certainly be one — are usually associated with both good and bad societal changes. What the Precautionary Principle says is that we should consider and mitigate as many of these negative consequences, and if we decide that they are too detrimental, not pursue the technology. It essentially asks us to reconsider the mindset of progress for progress’ sake, and incorporate planning and foresight into the process of technological development. Perhaps in the past the Precautionary Principle was too risk-averse to be effective, but it seems that now, with technology advancing more rapidly than ever, it would be wise to proceed a little more cautiously.

We need to check ourselves and critically examine the state of affairs to avoid as many of the potential pitfalls as possible. Molecular manufacturing could hold the answer to many of the most pressing problems of our time, but in order to keep it from spawning problems of its own we should proceed carefully and deliberately.


1. R.P. Feynman, “There’s Plenty of Room at the Bottom” (1959). Speech Delivered at the American Physical Society meeting, Pasadena, CA, 29 Dec 1959.
2. M. W. Browne, 2 Researchers Spell ‘I.B.M.,’ Atom by Atom (1990). Available at http://www.nytimes.com/1990/04/05/us/2-researchers-spell-ibm-atom-by-atom.html?scp=2
(20 June 2009).
3. B. Yurke et al., Nature 406, 605-608 (2000).
4. J. Amos, DNA Makes Tiny Tweezers (2000). Available at http://news.bbc.co.uk/2/hi/science/nature/873097.stm (21 June 2009).
5. J. Chen and N.C. Seeman, Nature 350, 631-633 (1991).
6. N.C. Seeman, Y. Zhang, T.-J. Fu, S. Zhang, Y. Wang and J. Chen, Chemical Synthesis of Nanostructures, Biomolecular Materials by Design: Materials Research Society Symposium Proceedings 330, 45-56 (1994).
7. F. Allhoff, P. Lin, J. Moor, J. Weckhart, Nanoethics: Ethical and Social Implications of Nanotechnology, Selected Writings of M. Treder and C. Phoenix (Wiley-Interscience, New York, 2007), pp. 311-323.
8. K. E. Drexler, Engines of Creation (Anchor, New York, 1987), pp. 171-191.
9. R. Strohmeyer, The 7 Worst Tech Predictions of All Time (2009). Available at http://tech.msn.com/news/articlepcw.aspx?cp-documentid=16829041 (20 June 2009).
10. E. Konopinski, C. Marvin, E. Teller, Technical Report, Los Alamos National Laboratory LA-602, (1946).
11. F. Allhoff, P. Lin, J. Moor, J. Weckhart, Nanoethics: Ethical and Social Implications of Nanotechnology, Selected Writings of J. Moor and J. Weckhart (Wiley-Interscience, New York, 2007), pp. 133-147.