The Promise and Peril of Nanotechnology
Director of Research, Center for Responsible Nanotechnology
Today, it takes a whole
economy to produce the technology that goes into a factory.
But this article describes a new technology that could produce
a tabletop manufacturing system—compact, flexible, and fast
enough to build a duplicate in an hour or so. That would be
For many purposes,
nanotechnology is defined as anything small enough to be interesting
and innovative. This can include large molecules, small minerals,
modern semiconductors, and a wide variety of sub-microscopic
structures with an equally wide variety of purposes. But nanotechnology
has another meaning, one that's even more interesting: using
programmable chemistry as the basis of a manufacturing system.
The first section of
this article describes how this will work. The second section
explains how powerful it could be. The third covers some possible
positive and negative consequences, and the fourth explains
why these consequences could happen within a decade. The conclusion
includes a call to action.
today is not precise. Pounding or pouring metal, squishing
plastic into shape, cutting things out of bigger things—all
are imprecise processes. But chemistry is perfectly precise.
A chemical bond is either there, or it's not. The results
of a chemical reaction are either right, or wrong. This means
that the product of chemistry can be specified exactly. Chemistry
If you wanted to build
a machine to paint a picture, you could plan a Rube Goldberg
collection of levers and gears that would move the brush in
just the right path. Or, you could attach a computer to a
few motors. The mechanics would be very simple. What would
be complex, in a computerized design, would be the software
running on the computer—and that could be as complex as you
liked. Systems that are programmable can make far
more complex products than systems that are not.
The picture on a computer
screen is built from a million tiny colored dots, controlled
by a billion 1's and 0's in the computer's software. By bringing
together all the little pieces, any desired image can be created.
A bottom-up system that can assemble zillions of
tiny pieces can make a product vastly more intricate and flexible
than a top-down system.
A precise digital system
is easy to automate. Your computer does trillions of calculations
per day without a single error. It can do this because it's
built around extremely reliable digital transistors. A manufacturing
system built around digital chemistry could also be extremely
reliable, producing thousands or millions of parts with exactly
the same chemical arrangement. (Several aspects of nanoscale
physics, including thermal noise and the squishiness of atoms,
also make nanoscale robotics easier in some ways than human-scale
industrial robotics.) As far as we can tell, it should be
feasible to completely automate a nanoscale manufacturing
The idea of molecular
manufacturing is to do chemistry, not by letting molecules
float around and bump into each other randomly, but by binding
and moving them where they should go. Biology does this to
some extent—many proteins have recognizable machinelike functions—but
biology is not completely digital and is only indirectly programmable.
The difference between molecular manufacturing and biology
is like the difference between a jet airplane and an eagle.
The bird's design is more subtle and flexible, and probably
more efficient, but the airplane is more powerful and can
fly faster and higher.
Power of Molecular Manufacturing
We don't yet know how
powerful molecular manufacturing could be, but estimates have
been made. Nano-built products should be very strong—somewhere
between steel and diamond. Computers and sensors should be
millions of times smaller and more efficient than today's
models. Motors may be thousands or even millions of times
more powerful, when they can be engineered at the level of
atoms and electrons.
The most detailed description of molecular
manufacturing was produced by Eric Drexler in 1992, in his
book Nanosystems. He proposes developing the ability
to make nano-parts out of diamond. Nanoscale robots could
do chemistry to build the diamond shapes a few atoms at a
time. Nanosystems calculated the chemical error
rate (very low), size of computers and machines (very small),
power density (very large), and strength (very high). Nanosystems
and subsequent work also calculated how fast a chemistry
robot could build stuff. It turns out that a plausible robot
could build its own weight in an hour or so.
Today's top-down manufacturing requires
hundreds of thousands of separate processes to build a complete
range of products, or even a complete range of manufacturing
equipment. A self-contained factory, one that included machinery
to build all its machinery, would have to be huge. But building
from the bottom up, adding a few atoms at a time in programmable
positions, shifts the complexity from the hardware to the
software. A relatively simple machine could easily make products
as complex as itself. And since chemistry is digital, it could
do so with a low error rate.
If you had a computer-controlled
“nanofactory” that could produce its own weight of product
in a few hours, what would you do with it? The obvious answer
is: build another factory! It'll only take a few hours, and
then you could produce twice as much stuff. As long as the
factory costs more than its products, the economical thing
to do is build more factories. Once these factories are a
glut on the market, the cost of equipment won't contribute
much to the cost of the product.
This implies that in
addition to being strong, compact, and powerful, products
of molecular manufacturing can be cheap — not much
costlier than the raw materials. This includes nanofactories:
a nanofactory will be able to rapidly produce its duplicate
from nothing but cheap chemicals and software. Make a tiny
fabricator build two fabricators fastened together, have them
produce four, then eight, and so on—and within a few weeks,
if all goes well, a microscopic fabricator has led to a tabletop
manufacturing system. It turns out that a tabletop nanofactory
could include 144 quadrillion chemical robots, about half
the weight of the factory, all working in parallel to build
their own weight in an hour or so. That means that bottom-up
nano-scale chemical construction can be used to build human-scale
of Molecular Manufacturing
Suppose you have a nanofactory that
can make almost anything you want, in almost any quantity,
at very low cost. Do you live happily ever after? Or do you
worry about what your neighbors are doing with their nanofactories?
Unfortunately, we probably
have to worry. One nasty neighbor could ruin everyone's day.
A country that designed and built lots of cutting-edge weapons
potentially could take over the world. That possibility could
easily lead to an arms race—one a lot less stable than the
nuclear arms race, because weapons development would be much
cheaper, faster, and easier to hide. Criminals could send
smart bugs to spy on you or make your life miserable unless
you paid protection money. Wastrels could easily build enough
nano-litter to destroy the environment. Cheap personal manufacturing
could disrupt economics and trade, destabilizing the world's
current political systems.
if once released to the public, would be very hard to control.
A miniature self-contained nanofactory could be the size of
a grain of salt: impossible to detect in a search, but easily
doubled and redoubled to create a large manufacturing system.
This argues that strict control should be maintained over
any nanofactory that's developed.
The trouble with a
regime of strict control is that everyone will want easy access
to nanofactory manufacturing—and most people should have it.
Molecular manufacturing has the potential to solve many of
the world's most urgent problems. Cheap, clean, local, self-contained
manufacturing could rapidly wipe out poverty while simultaneously
reducing our environmental footprint. Medical devices as well
as weapons could be built cheaply. Large-scale engineering
projects could be far less costly and more inventive, allowing
the rapid development and installation of new systems for
energy and agriculture. Some people think that only molecular
manufacturing can solve the current environmental crisis.
The technology should
not be prevented. Indeed, it cannot be—it will rapidly become
easier to develop. But it also cannot be allowed to spread
unchecked. So much power in the hands of millions of people
and organizations would lead to instability, and then disaster.
But controlling this situation would require incredible concentration
of power. Massive distributed power would lead to massive
distributed disasters. Massive concentrated power could easily
lead to totalitarianism. We must find a solution to this—and
How long till molecular manufacturing
is developed? It could be less than a decade. Already, we
can build relatively large bottom-up nanosystems with chemistry—hundreds
of atoms wide. Top-down fabrication processes can build things
smaller than that. A hybrid technology, though awkward, could
be used to “bootstrap” a fully bottom-up technology. With
heavy funding, this might be done in the next few years, and
it will rapidly get easier.
The cost of developing
molecular manufacturing depends on the cost of computers,
which is dropping by half every two years. The cost also depends
on how many lab techniques need to be invented. Already, we
can make machines (top-down) small enough to physically grab
individual molecules (bottom-up), and the pace of progress
continually surprises me.
Ten years ago, a rapid
development program would have had to try many false paths,
multiplying the cost. Today, it would be much easier to decide
which development pathways to focus on. Experimental work
on many nanoscale technologies is quickly showing what each
technology is capable of. Theoretical work continues to refine
the molecular manufacturing concept, showing what is needed.
Considering all these factors, I predict that the cost of
developing molecular manufacturing will fall by half every
two years or so.
In my opinion, a well-managed,
well-funded program on the level of the Manhattan Project
could almost certainly develop molecular manufacturing in
less than ten years—perhaps as few as five. If such a program
has already started somewhere in secret, it might finish in
the next few years. Five years from now, even if no government
has funded a Manhattan Project, the lower cost and greater
certainty will probably make a five-year development plan
attractive to a number of large corporations.
Molecular manufacturing is based on
a few simple, powerful ideas: programmable control, bottom-up
chemical fabrication, automation, and the ability of a small
factory based on these principles to rapidly make one twice
as big. Biology comes close to achieving this, but engineering
should easily be able to improve on biology, at least for
simple tasks. (Remember, biology never developed the wheel.)
We should plan for
the possibility of molecular manufacturing being developed
in less than a decade. To ignore this possibility would be
imprudent, to say the least. Molecular manufacturing has the
power to correct environmental and humanitarian disasters,
but will also create new and potentially disastrous problems.
The power of molecular
manufacturing is too great to be released randomly. However,
good administration of the technology will not be easy to
design. The Center for Responsible Nanotechnology believes
that this is one of the most urgent issues facing the world
today. We need better studies of the development schedule
and the range of possible consequences. We need to develop
systems of administration that can handle the unprecedented
power of the technology. Public awareness will be crucial;
we can't prepare for what we don't know about.
Think about how molecular
manufacturing would change your life. Ask yourself and your
co-workers what impact it would have on the plans you make.
Learn more about it: Foresight.org and CRNano.org are good
places to start. Begin questioning ten-year projections that
do not take the possibility into account. If we do not prepare
ourselves for molecular manufacturing, it will take us by
surprise—and a surprise of this magnitude will almost certainly
This essay is original and was specifically prepared for publication at Future Brief. A brief biography
of Chris Phoenix can be found at our main Commentary
page. Recent essays written by Mr. Phoenix can be found at his
Center for Responsible Nanotechnology.
Some earlier essays are archived at Nanotechnology Now.
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© 2004, Christopher Phoenix,
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