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Results of Our Ongoing Research
These pages, marked with
GREEN headings, are published for
comment and criticism. These
are not our final findings; some of these opinions will probably change.
LOG OF UPDATES
CRN Research: Overview of Current Findings
Estimating a Timeline for Molecular
Manufacturing
Overview:
Molecular manufacturing (MM) means the ability to build devices, machines, and
eventually whole products with every atom in its specified place. Today the
theories for using mechanical chemistry to directly fabricate nanoscale
structures are well-developed and awaiting progress in enabling technologies.
Assuming all this theory works—and no one has established a problem with it
yet—exponential general-purpose molecular manufacturing appears to be
inevitable. It might become a reality by
2010 to 2015,
more plausibly will by 2015 to
2020, and almost certainly will by 2020 to 2025. When it arrives, it will come quickly.
MM
can be built into a self-contained,
personal factory (PN) that makes cheap products
efficiently at molecular scale. The time from the first
fabricator to a flood of powerful and complex
products may be less than a
year. The potential benefits of such a technology are immense. Unfortunately,
the risks are also immense.
| Molecular
manufacturing can make large,
complex products with almost every atom precisely placed. |
The goal of molecular
manufacturing (MM)
is to build complex products with almost every atom in its proper
place. This requires creating large molecular shapes and then assembling
them into products. The molecules must be built by some form of chemistry.
Many MM proposals assume that building shapes of the required variety and
complexity will require robotic placement (covalent bonding) of small
chemical pieces. Once the molecular shapes are made, they must be combined
to form structures and machines. Again, this is probably done most easily
by robotic assembly. Theoretical studies have shown that it should be
possible to build diamond lattice by mechanically guided chemistry, or
mechanochemistry. By building the lattice in various directions, a wide
variety of parts can be made—parts that would be familiar to a mechanical
engineer, such as levers and housings. A robotic system used to build the
molecular parts could also be used to assemble the parts into a machine. In
fact, there is no reason why a robotic system can't build a copy of itself. In sharp contrast to conventional manufacturing, only a few (chemical)
processes are needed to make any required shape. And with each atom in the
right place, each manufactured part will be precisely the right size—so
robotic assembly plans will be easy to program.
A small nano-robotic device that can use supplied chemicals to manufacture
nanoscale products
under external control is called a
fabricator. |
| |
More than forty years ago, Richard Feynman
said, "The principles of physics, as far as I can see, do not speak against
the possibility of maneuvering things atom by atom." Molecular
nanotechnology includes only one additional, and relatively easy, step:
combining the small shapes and machines produced by individual chemical
workstations into large products. The easiest way to do this is to combine
small pieces into larger pieces, and then join those to make still larger
ones. This process is called
convergent assembly, and it can be used
to make products large enough to be used directly by people. CRN has
published a peer-reviewed paper, titled "Design
of a Primitive Nanofactory", showing how large numbers of fabricators
can be combined to create a
personal nanofactory
(PN) capable of making human-scale
products. It appears that this might be accomplished in as little as a few
months after the first fabricator is built. The resulting PN would be easy to program to make a wide
variety of products, including duplicate PNs. |
| Molecular
manufacturing will be highly desirable for both commercial and military
projects. |
Although there are
several possible ways to develop an MM capability, the best way appears to be the creation of
fabricators and then nanofactories that can make diamond lattice (as
explained above). Diamond is very strong, and can be used to build a wide
variety of useful gadgets including motors and computers. This implies that
the products of a nanofactory will also be strong, and that active
functionality can be extremely compact. For example, an engine powerful
enough to drive a car would fill less than a cubic centimeter, and a modern
supercomputer would require less than a cubic
millimeter. Diamond structure
would be at least ten times as strong as steel for the same weight—probably
closer to 100 times as strong. Because of the simple, and massively
parallel, manufacturing used by a nanofactory, the complexity of a product
would not affect either the manufacturing cost or the time to build it. A
new design—any new design—could be built in just a few hours. A
nanofactory, like an fabricator, will be able to duplicate itself. Nanofactories will be as cheap as any other product, so any desired number
of nanofactories can be built. Since nanofactories can be used for final
manufacturing as well as rapid prototyping, product design will not have to
concern itself with "manufacturability." As soon as a prototype is
designed, it can be built. As soon as the prototype is approved, mass
production can be started—and finished a few hours later. |
| |
The design of an
MM version of a product will actually be easier than today's process.
Instead of designing a shape and then worrying about how to whittle down a
block of material or carve out a mold, the designer simply specifies the
shape—and the nanofactory will create diamond structure to fill the
specified volume. Instead of worrying about fastening parts together, the
designer can simply tell the CAD software that they should be attached. The
surfaces to be joined will be covered by the CAD software with a simple
mechanical interlocking mechanism (described in CRN's
Nanofactory paper), and the
convergent assembly process only needs to press them together. Because
power and computer functionality will be much smaller than today's devices,
the designer will have much less difficulty in making the functional parts
of the design fit into the space required. And because a vast range of
products can be specified by a single CAD system and manufactured by a
single nanofactory design, a well-trained MNT designer will be able to
design a large number of products, just as a well-trained software engineer
can write a wide variety of programs. |
| |
The strength and
power of products, the compactness of their functional components, and the
ease and speed of design and production, combine to make MM a very useful technology. Vast
amounts of money can be saved in the product design process, in
manufacturing, in distribution and warehousing. New product lines can be
designed, manufactured, and marketed in a few weeks. The same efficiencies
apply to military hardware as well. Each new weapons system could be
developed and deployed much more quickly and cheaply. Prototypes and tests
would be generated much faster and cost far less. Since a prototype design
could be immediately manufactured in any desired quantity, deployment would
also be much faster. New kinds of weapon systems could be contemplated. Both commercial and military/governmental organizations will have a strong
incentive to fund the rapid development of MM, even at a cost of
billions of dollars. |
| It's a very short step from
a fabricator to a nanofactory.
(MORE) |
As described
above, a fabricator is a small machine that can create precise shapes out of molecules, assemble
those shapes into machines, and ultimately duplicate itself when supplied
with the necessary broadcast instruction stream. The
duplication is necessary because a single fabricator could not build more
than a small number of tiny products. A fabricator is a worthwhile goal,
because although it can't make large products, many fabricators can be
combined to form a nanofactory. CRN has published a technical
paper describing the process and techniques required to
bootstrap from a sub-micron
fabricator to a personal nanofactory; it appears that this can be done
in a few months if suitable design and analysis is done beforehand. So we
can assume that a fabricator project will include a nanofactory project, and
that a useful nanofactory will appear within months of the first fabricator. |
| Once the first nanofactory
is built, a flood of products will follow. |
A wide range of
products can be designed simply by sticking small functional blocks
together; the joining process is covered in detail in the
paper
mentioned above. Effectively, then, the question of when we will see a flood
of MM-built products
boils down to the question of how quickly the first fabricator can be
designed and built. Once the first desktop nanofactory has been built, its
first product likely will be another identical nanofactory. Then, following
the simple math of exponential duplication, it's easy to see that within
months millions or even billions of personal nanofactories conceivably could
be in operation. A key understanding of MM is that it leads not just to improved products, but to a vastly improved
and accelerated means of production. |
| Most of today's nanotech is different from molecular
manufacturing. |
There is a difference between molecular
manufacturing technology and today's nanomaterials research and other
nanoscale
technologies. Most of the nanotech work now being funded involves building
small structures and searching for novel properties, then figuring out ways
to use these new properties in new products. This is very useful work, and
in many cases will be very profitable. But it is quite different from MM,
which is concerned with building a single device: a flexible, easy-to-use,
preferably large-scale, molecular manufacturing system. (Of course, once
created this system could immediately start making a wide range of
products.) Some results of current nanotechnology research will be
enabling technologies for MM: technologies that make it easier to build
a fabricator. Non-nanotech fields will also contribute enabling
technologies. |
| Designing a fabricator will be hard but
feasible. (MORE) |
Designing a
fabricator will not be easy.
Mechanochemistry, the formation or breaking of chemical bonds under direct
mechanical control, has been demonstrated, but it will take a lot more work
to develop the mechanochemical techniques to build diamond and other strong
materials. These techniques will require some basic research; however,
preliminary work (by Eric Drexler, Robert Freitas, Ralph Merkle, and John
Michelsen, for example) shows that there are several different kinds of
mechanochemical reactions that should be able to build diamond. Unless all
this work is wrong and no other techniques can be discovered,
building atomically precise
diamondoid shapes will be possible. The
small-scale robotic device to do the required mechanochemical operations has
to be designed, including the control system. This is mostly a matter of
simple mechanics. The integration of the mechanochemical device with other
devices to support the parts and product, deliver "feedstock" chemicals from
an uncontrolled exterior to a well-controlled interior, and so on should
also be relatively straightforward—at least compared with designing a
spacecraft. |
| |
A modern spacecraft contains millions of
parts (estimates for the Space Shuttle range from 2.5 to six million). A
large spacecraft design must account for fluid dynamics, aerodynamics,
vibration and resonance on many time scales, avionics and other control,
chemical engineering, mechanical engineering, electrical engineering,
combustion dynamics, hydraulics, cryogenics, and biomedical issues. (Thanks
to an
anonymous poster on
Slashdot
for pointing this out.) By contrast, a fabricator design must account for
chemistry, mechanical engineering including stiffness, control structures,
and a different set of forces than we're used to at the macro-scale (e.g.
van der Waals force). Note that many problems can be treated as mechanical
engineering issues without greatly increasing the size and complexity of the
fabricator. One example is thermal noise: as analyzed in
Nanosystems,
if the parts are stiff enough, it's not a problem even at room temperature. |
| Building the first
fabricator will also be
hard. |
Building the first
fabricator may be even
harder than designing it. (Building the second and subsequent fabricators will be relatively easy.) If the first
fabricator is diamond-based, the
diamond must be formed in small precise shapes without the benefit of
fabricator mechanisms. If the first fabricator is built of DNA, protein, or
other "wet" chemistry products, it must either work underwater while
protecting the workpiece, or must work after being dried. Neither of these
option is very attractive. However, we are already learning to do
mechanochemistry and nanomanipulation with scanning probe microscopes. The
use of buckytubes as scanning probes is fairly new, but is already proving
useful. There are a variety of potential ways to build structures even
smaller and more precise to do the required chemistry. Again, unless every
single possibility we can think of turns out to be unfeasible, a fabricator can be built. |
| We have lots of enabling technologies
already. |
We don't yet know
whether the enabling technologies we have today are far enough advanced to
start a molecular fabricator project. Enabling technologies are of four basic types: fabrication,
manipulation, sensing, and simulation. First, we'll need to make very small
parts with intricate shapes. Semiconductor lithography is making features a
few tens of
nanometers wide. Buckytube welding in an electron microscope
has been demonstrated, and also growing buckytubes along templates,
including branching templates. Dip-pen nanolithography promises to make
built-up 3D structures with a variety of different chemicals and 2.5-nm
feature size. We have the ability to make molecule-sized molds and deposit
a few atoms of metal into them. We can design a few structures with
self-assembling DNA and other chemicals. There are many other techniques
that we don't have space to list here. Second, we'll need to move those
parts into the right position to assemble machines. Possible techniques
include optical tweezers, pushing with scanning probes, microfluidics,
biological motors, and constructed motors such as the "DNA Tweezers". Third, we'll probably need to see what we're doing. Electron microscopes
can resolve a few nanometers. Proximal probes can resolve fractions of an
angstrom. We may even get help from sub-wavelength optical techniques,
including near-field optical probes, photon entanglement, and several kinds
of interferometry. Some of these may not be useful in practice, but
near-field optical probes have already been demonstrated and used. The
fourth enabling technology is simulation. Computers are getting faster,
algorithms are improving, and we can already simulate hundreds or thousands
of interacting atoms. |
| Fabricator
design is probably no harder than some projects we've already done. |
If a fabricator
project is not feasible today, it will surely be feasible in a few years.
Most of the enabling technologies mentioned here, and many others as well,
are being actively developed for their present-day commercial potential. As
the technologies develop, they will reach a point where they can easily be
re-used in a fabricator project. The mechanics of the project will become
far easier in just a few years. The chemistry will become easier as more
powerful computers are developed for simulation, but already it is feasible
to test individual reactions in simulation. The question is not whether a
fabricator project is feasible, but when it will become economically viable or a
military necessity.
|
| |
A new, large spacecraft or weapon system costs tens of
billions of US$ to develop, and molecular nanotechnology will be far more
useful than any single aerospace or weapons system. In today's dollars,
total development cost for the original Space Shuttle was probably around
$10-15 billion. At that rate, each part would have cost an average of
$2,000-$6,000 to design. How many parts will a fabricator require?
Estimates of the atom count, based in part on comparisons with bacteria,
frequently come in around 1 billion atoms. Diamond has 176 carbon atoms per
cubic nanometer, so if each part were only one cubic nanometer, a fabricator
might have 6 million parts—comparable to the Shuttle. With parts 10
nanometers on a side, it would have only 6,000 parts. For comparison, a
typical four-cylinder automobile engine has about 450 parts and a bacterium
may have 3,600 different molecules. As opposed to a "wet" design like a
bacterium or a cutting-edge aerospace design, most of a fabricator's parts
would not interact with each other and could be designed separately. It
appears, then, that design of a fabricator falls somewhere between a car
engine and the Space Shuttle in complexity. Construction, if not feasible
today, will be feasible soon. |
| A fabricator within a decade is
plausible— maybe even sooner. |
The Space Shuttle took less than ten years
to design and build, from 1972 to 1981. The atomic bomb took only three
years, from 1942 to 1945. Both of these programs involved more new science
research and more development of new technologies and techniques than an
assembler program would likely require. As analyzed above, they probably
cost more too. The main question in estimating a timeline for fabricator
development, then, is when it will be technically and politically feasible.
There are probably five or more nations, and perhaps several large
companies, that could finance a molecular fabricator effort starting in this decade. The technical feasibility depends on the enabling technologies. Even a
single present-day technology, dip-pen nanolithography, may be able to
fabricate an entire proto-fabricator with sufficient effort. At this point,
we have not seen anything to make us believe that a five-year $10 billion
fabricator project, starting today, would be infeasible, though we don't yet
know enough to estimate its chance of success. Five years from now, we
expect that a five-year project will be obviously feasible, and its cost may
be well under $5 billion.
|
| |
The National
Science Foundation, and others, have
estimated
that even non-MM nanotechnology will be worth a trillion
dollars or more by 2015. By the time people realize that it's possible to
build a nano-based manufacturing system, it will probably be obvious that
such a project would be quite profitable (in addition to the military
imperatives). This implies that companies and/or governments will start
crash programs, comparable perhaps to the Manhattan project. Of course
there are other development scenarios, but we feel this is one of the more
likely ones. We also
cannot rule out the possibility that a
large, well-funded, secret development program for molecular manufacturing
has been in operation somewhere for several years and may achieve success
sooner than any public program. |
|
Additional Reading: |
See our page,
Focusing on
Fabricators, highlighting a commentary by nanotechnology researcher
Ralph Merkle. |
DEVIL'S ADVOCATE —
Submit your criticism, please!
A lot of nanotechnologists have said that a fabricator is too complicated and difficult to be worth building.
Remember that molecular nanotechnology and current
nanomaterials research are two different fields. These people are today's
nanotechnologists, and with all due respect, they are talking outside their
area of expertise. The savings in semiconductor processing alone would make
MNT worth doing at any price under $10 billion, and the same is true for
hundreds of other fields.
But the laws of physics say that...
The laws of physics, including quantum uncertainty, thermal
noise, Heisenberg uncertainty, tunneling, and resonance, do not appear to pose
severe problems.
Nanosystems explained in detail how mechanical
chemistry can be accomplished at room temperature with better than 1 in 1015
error rates. Things are a little different at small scales, but after all, the
cells in your body use molecular machines made of floppy protein and they work
just fine.
The theory may work, but it takes decades to develop
stuff in real life.
That depends on how much pure research has to be done, and
how much of the job is just engineering. It also depends on the amount of
money that's thrown at a problem, and the creation of a project management
structure that can use the money efficiently. Even the Space Shuttle took less
than a decade, and the atomic bomb took one-third that. Aside from some
chemistry, a molecular fabricator will not require much pure research, and a
useful nanofactory will require very little additional research since it can
be designed at the mechanical level.
In December, 2007, reader Rick Cook offered this
objection:
Your timeline for fabbers isn't just wildly optimistic,
it's as close to flat impossible as anything I've seen this side of Young Earth
Creationism. For starters, there is an enormous difference between having a
proof of principle device running in a lab, to having a working prototype, to
having a pilot model in limited production to having something in full-scale
production. Not to mention the time it takes for even the most wildly popular
device to be widely adopted and finally for those effects to work their way
through society.
It takes time. Each of those steps takes time and usually a number of
false starts and development cycles. And by time I mean years, especially in the
early phases.
However to me the biggest problem, which overshadows all
the others, is you're proposing trying to regulate a process none of us
understand at all clearly. Given the history of similar efforts, it's almost a
certainty that anything we do now to control nanotechnology (however defined) is
going to be wrong. We don't know where the technology is going or how it's going
to affect us. If we try to control it now we will undoubtedly strain at gnats,
which will ultimately be unimportant, while being trampled into the dust by the
herd of rampaging camels we didn't see coming.
Thanks, Rick, for your input. Below is part of our full
response (read the rest here):
CRN doesn't talk about the possible emergence of molecular
manufacturing by 2015-2020 because we think that this timeline is necessarily
the most realistic forecast. Instead, we use that timeline because the purpose
of the Center for Responsible Nanotechnology is not prediction, but
preparation.
Recognizing that this event could plausibly happen in the next decade -- even
if the mainstream conclusion is that it's unlikely before 2025 or 2030 --
elicits what we consider to be an appropriate sense of urgency regarding the
need to be prepared. Facing a world of molecular manufacturing without
adequate forethought is a far, far worse outcome than developing plans and
policies for a slow-to-arrive event... MORE ON
THIS TOPIC
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Overview of Current Findings
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