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Reprinted with permission from Foresight Update 14:
On June 26, 1992, the U.S. Senate Committee on
Commerce, Science, and Transportation's Subcommittee on
Science, Technology, and Space held a hearing on the
topic of "New Technologies for a Sustainable
World." Dr. Eric Drexler, Chairman of the Foresight
Institute and Research Fellow of the Institute for
Molecular Manufacturing, was invited to testify on
molecular nanotechnology. The following is the written
testimony he submitted; a later issue will cover the oral
portion.
Summary:
In 1959, the Nobel prizewinning physicist Richard
Feynman suggested that individual atoms and molecules
could be positioned and used as building blocks;
experimental results now demonstrate that he was correct.
Molecule-by-molecule control can become the basis of a
manufacturing technology cleaner and more efficient than
those known today. This molecular nanotechnology will
resemble processes in farms and forests, in which
molecular machines convert common raw materials -
including surplus atmospheric carbon dioxide - into
useful products. It can be a basis for sustainable
development, raising the material standard of living
while decreasing resource consumption and environmental
impact. Molecular nanotechnology will have broad
applications. It will provide a general-purpose method
for processing materials, molecule by molecule, much as
computers provide a general-purpose method for processing
information, bit by bit. It will by its nature be highly
efficient in both materials and energy use. Its products
can include:
- Clean, highly productive manufacturing systems
- New molecular instruments for science and
medicine
- Extremely compact, energy-efficient computers
- Stronger materials for lighter and more efficient
vehicles
- Inexpensive solar cells suitable for use in
roofing and paving
Analysis and simulation based on existing scientific
knowledge is enough to show what molecular nanotechnology
can do, but developing it will require the construction
of better molecular tools. The pace of development will
depend not on unpredictable breakthroughs, but on the
magnitude and quality of a focused development effort.
The total development time is hard to predict, but 15
years would not be surprising. Unlike some technology
development projects, in which few payoffs result until
the end of the development cycle, research in molecular
nanotechnology will bring major scientific benefits at an
early date. Molecular nanotechnology is worth pursuing
both for its immediate scientific benefits and for its
later environmental benefits. Because there is reason to
think that it will become the basic manufacturing
technology of the 21st century - on grounds of cost,
quality, efficiency, and cleanliness - its development
also raises issues of economic competitiveness. Japan's
Ministry of International Trade and Industry has recently
committed some US$185 million over ten years to a
nanotechnology effort. The U.S. research community has
not yet reached a conclusion regarding the potential of
this field because it has not yet addressed the basic
scientific issues. If we conduct idle debates on
molecular nanotechnology while others conduct active
research, they will learn the answers to our questions.
It is time to assess the potential of molecular
nanotechnology and to choose a course of action. If its
potential is even half as great as the evidence now
indicates, then medical, economic, and environmental
concerns will favor vigorous development.
Introduction
Mr. Chairman, I would like to thank you and the
members of this subcommittee for this opportunity to
discuss a topic that I expect will one day become a
leading issue in these halls. The focus of this hearing -
new technologies for a sustainable world - is
particularly appropriate for discussion of this topic,
because a concern with the consequences of future
technologies for the environment and for the human
condition has for many years guided my research, and has
led to the results described here.
In the decade since I first described molecular
nanotechnology in the Proceedings of the National Academy
of Sciences, this field has progressed from general
theoretical concepts to early laboratory demonstrations
and a growing body of detailed designs. Five years ago,
audiences questioned whether individual atoms could be
placed in precise patterns; today, I can answer that
question not just with calculations, but with a slide
showing the letters IBM spelled using 35 xenon
atoms. The Foresight Institute, which I serve as
chairman, sponsors a series of scientific conferences on
molecular nanotechnology. The most recent, held last
autumn, was cosponsored by the Stanford University
Department of Materials Science and Engineering and the
University of Tokyo Research Center for Advanced Science
and Technology; this meeting has stimulated at least
three laboratory research efforts directed toward a key
milestone on the path to molecular nanotechnology.
Japan's Ministry of International Trade and Industry
recently committed some US$185 million over the next 10
years to a nanotechnology research effort; development of
molecular systems is seen in Japan as fitting with the
broad goal of developing environmentally-compatible
technologies. Momentum toward the development of
molecular nanotechnology is building around the world.
The consequences for human life and for Earth's
environment will be enormous, and could be enormously
positive. The balance of this testimony begins by
describing molecular nanotechnology from a biological and
ecological perspective and sketching some of its wide
range of applications. It then describes the relevant
areas of research; the level of activity in the Unites
States, Japan, and Europe; and some of the policy issues
that its development can be expected to raise. The
closing section discusses how these concepts can be
evaluated before committing to any substantial effort
that presumes their validity.
A biological and ecological perpsective
Industry today consumes fossil fuel and discharges
carbon dioxide into the atmosphere. Forests and farms, in
contrast, produce useful products (including fuels) while
removing carbon dioxide from the atmosphere. Proposals
for reducing the concentration of greenhouse gases
typically focus on modifying existing industrial
technologies to reduce emissions, and this is a sound
strategy. Yet it may be better to develop industrial
technologies that, like forests and farms, are carbon
dioxide consumers. Leaves are solar energy collectors
employing molecular electronic devices: chlorophyll
molecules and photosynthetic reaction centers. These
solar energy collectors, like the other useful products
of forests and farms, are built by systems of molecular
machinery such as ribosomes and metabolic enzymes. A
natural direction for technology, then, is to learn to
apply systems of molecular machinery to build useful
products in industry.
The example of green plants indicates some of the results
that can be expected from molecular nanotechnology:
- Low-cost production of solar collectors
- Low-cost production of large structures
(though stronger than wood)
- No production or disposal of toxic chemicals
- Absorption of atmospheric carbon dioxide
- Compatibility with the natural world
Although no technology can, by itself, solve
environmental problems, a technology with these
characteristics can be a great help. If a high standard
of living and reduced environmental impact can be
achieved with relatively little sacrifice, then any given
amount of political and regulatory pressure should yield
greater results in reducing the impact of human
activities on the natural world.
Taking the biological analogy as far as the preceding
paragraphs have done risks the misunderstanding that
molecular nanotechnology will be a form of biotechnology.
The differences are large: Molecular nanotechnology will
use not ribosomes, but robotic assembly; not veins, but
conveyor belts; not muscles, but motors; not genes, but
computers; not cells dividing, but small factories making
products - including additional factories. What molecular
nanotechnology shares with biology is the use of systems
of molecular machinery to guide molecular assembly with
clean, rapid precision. Another biological analogy seems
appropriate: Aircraft and birds share some basic
principles of flight, and birds inspired the development
of mechanical flight. It would have been futile, however,
to attempt to develop aircraft by applying genetic
engineering to birds, or by concentrating exclusively on
ornithological research. The Wright brothers studied
birds, but they then set off in a fresh direction.
Molecular nanotechnology cannot be achieved by tinkering
with life, and its products will differ from biological
organisms as greatly as a jet aircraft differs from an
eagle.
Range of applications
Molecular nanotechnologies will be based on molecular
manufacturing, a fundamentally new way to produce
materials and devices from simple raw materials. By
guiding the assembly of molecules with precision, it will
enable the construction of products of unprecedented
quality and performance. Because it will work with the
fundamental molecular building blocks of matter, it will
be able to make an extraordinarily wide range of
products. Computers provide an analogy. In the early
decades of this century, many specialized data-processing
machines were in use: these included the Hollerith
punched-card tabulators used in the census, Vannevar
Bush's analogue machine that solved differential
equations for scientists, and adding machines used in
offices to speed accounting chores. Each of these slow,
inefficient, specialized machines has now been superseded
by fast, efficient, general-purpose computers; even
pocket calculators contain computers. By treating data in
terms of fundamental building blocks - bits -
general-purpose computers can perform essentially any
desired operation on that data.
Today, manufacturing relies on many specialized machines
for processing materials: blast furnaces, lathes, and so
forth. Molecular nanotechnology will replace these slow,
inefficient, specialized (and dirty) machines with
systems that are faster, more efficient, more flexible,
and less polluting. As with computers and bits, these
systems will gain their flexibility by working with
fundamental building blocks. When desktop computers
replaced adding machines, they did more than speed
addition. Molecular manufacturing will likewise open new
possibilities. The applications of precise fabrication at
the molecular level (mechanosynthesis) are as broad as
technology itself, because all of technology relies on
manufacturing. Molecular-scale components can be used to
place the equivalent of a billion modern computers in a
desktop machine. Molecular-scale components will make
possible new medical and scientific instruments,
including DNA readers able to sequence genomes routinely.
On a larger scale, production of better materials will
make possible lighter, more efficient vehicles, without
sacrificing structural strength: this will aid
transportation technologies ranging from spacecraft to
automobiles. Lighter structures will consume less
material and energy. Because the lightest and strongest
materials will be made from carbon (in the form of
graphite and diamond fibers), carbon dioxide can become a
raw material rather than a waste product. Molecular
manufacturing systems can be used to make more molecular
manufacturing systems, hence the capital cost of
production can be low. An analysis of inputs, outputs,
and productivity suggests that the total cost of
production can be in the range familiar in agriculture
and in the production of industrial chemicals - tens of
cents per pound. At this cost, many applications become
practical. For example, solar photovoltaic cells
fabricated in the form of tough sheets for roofing and
paving could provide solar electric power without
consuming additional land. With clean solar power, clean
manufacturing processes, and light, efficient products,
it will be possible to provide a high-material standard
of living with decreased impact on the natural world.
This can contribute to the goal of sustainable
development.
Research directions and funding
These developments are not around the corner, but
their feasibility can be clearly foreseen, as can the
nature of research programs able to implement them. The
essential goal is to construct molecular structures with
the precision already familiar in chemical synthesis and
protein engineering, but on a larger scale. Accordingly,
properly focused research in chemical synthesis and
protein engineering (within the fields of molecular
biology and biochemistry) is important to the
implementation of molecular nanotechnology, as is the
emerging field of molecular manipulation using proximal
probe microscopes such as the scanning tunneling and
atomic force microscope. Each of these areas is a classic
small-science field, in which small teams use inexpensive
materials and equipment. The prospect of molecular
nanotechnology shows that small science can have big
rewards.
. . .
I have not requested and do not anticipate a need for
Federal funds to support my own studies in this area, but
the field as a whole could benefit from vigorous support
of appropriate computational simulation and laboratory
research. Since this work would be performed chiefly by
existing researchers with existing equipment, the need is
more for a shift in direction than for a growth in
spending. Developments along the path to molecular
nanotechnology promise to yield early results in
scientific instrumentation, making it justifiable as a
means of pursuing existing goals in chemistry and in
biomedical research.
Progress toward molecular nanotechnology in the United
States has been retarded chiefly by cultural obstacles.
Molecular nanotechnology will require the construction of
complex molecular machines, but chemistry and
biochemistry are sciences, and focus on the study of
nature. To return to the example of aerospace
engineering, expecting molecular scientists to build
molecular manufacturing systems is somewhat like
expecting ornithologists to build aircraft. Building
complex systems demands research that first defines goals
and then works backward to identify and implement the
means, usually dividing the work among many teams.
Studying nature, in contrast, can be performed by small
research groups, each jealously guarding the independence
and purity of its research. The development of molecular
nanotechnology can keep much of the character of small
science, but it will require the addition of a
systems-engineering perspective and a willingness on the
part of researchers to choose objectives that contribute
to known technological goals. Progress will require that
researchers build molecular parts that fit together to
build systems, but the necessary tradition of design and
collaboration--fundamental to engineering progress--is
essentially absent in the molecular sciences today.
Furthering molecular nanotechnology might best be
achieved by directing federal agencies that perform or
fund research in the molecular sciences to support
efforts aimed at the construction of molecular machine
systems and instruments that can precisely position
molecules. The results of this initiative could lead to
cost savings in other programs. It has been proposed, for
example, that thousands of researchers be employed over
many years at great expense in order to read the human
genome, yet the molecular machinery found within a
dividing cell reads (and copies) the entire genome in a
matter of hours. Scientific instruments based on
relatively simple molecular machines could read DNA with
comparable speed and store the results in a computer
memory. The development of such instruments, once the
necessary technology base is in place, could hardly
consume the efforts of thousands or researchers; it would
more likely require only a few cooperating laboratories.
The result would enable scientists to read and study many
genomes.
Molecular machinery is a technology of basic importance
and deserves to be treated accordingly. This would be
true even without the longer term goal of molecular
manufacturing.
Research in the Unites States, Japan, and Europe
The Unites States has impressive strengths in areas of
science and technology relevant to molecular
nanotechnology. It was at IBM's Almaden laboratory that
Donald Eigler's group spelled IBM using 35 xenon
atoms. It was at William DeGrado's laboratory at DuPont
that scientists first designed and built a new protein
molecule, containing hundreds of precisely joined atoms. Nanotechnology
has become a buzzword, but is often used to describe
incremental improvements in existing semiconductor
technologies; although of great value in their own right,
these are of surprisingly little relevance to molecular
nanotechnology. (Micromachine research, often confused
with nanotechnology in the popular press, is even less
relevant.) Progress toward molecular nanotechnology in
Japan is harder to judge, owing to distance and language
barriers, but the Japanese commitment appears impressive.
In my visits to Japan, I have received a strikingly warm
welcome. MITI organized a symposium around my first
visit, at which - despite my many talks in the U.S - I
for the first time met other researchers who were
studying molecular machines not only to understand
nature, but to build molecular machine systems. On
another visit, I spoke at the only scientific meeting on
the construction of molecular machine systems that I have
attended but did not myself organize. Japan's NHK
television network aired a three-hour series this spring,
titled "Nanospace," that included interviews
with me and material from my work; nothing comparable has
appeared on U.S. television.
While exploring a Japanese-language bookstore that I
happened across in Tokyo last spring, I found a table
with eight books on micromachines and molecular machines,
all displayed face on. Half were paperbacks (including
conference proceedings containing a summary of a talk I
had given in Tokyo two years before), and half contained
one or more graphics illustrating molecular machine
designs drawn from my work. One of these was a
translation of my first book on molecular nanotechnology,
Engines of Creation. I can with confidence state
that no bookstore in the Unites States contains a similar
display, because no such set of books exists in the
English language.
MITI's commitment of US$185 million is a sign of strong
interest. In addition, Japan's Science and Technology
Agency, through the Exploratory Research for Advanced
Technology program, has sponsored a series of efforts in
molecular engineering, including the Aono Atomcraft
Project, which aims to build semiconductor devices with
atom-by-atom control. I recently read that Texas
Instruments has established a laboratory with similar
goals; the location they chose is Tsukuba, north of
Tokyo. Researchers at Hitachi's Central Research
Laboratory last year spelled Peace 91 HCRL by
removing individual atoms from a surface. Researchers at
the Protein Engineering Research Institute in Osaka (no
comparable institute exists in the Unites States) have
designed and built the largest protein molecules of which
I am aware. Nanotechnology has been a serious goal in
Japan for longer than it has in the Unites States, and is
seen as a contributing to technologies in greater harmony
with the natural world. I am less familiar with research
in Europe, but key technologies (such as the
scanning-tunneling microscope) have been developed there.
Dr. Hiroyuki Sasabe of the RIKEN Institute in Japan tells
me that there are several research consortia in Europe
doing work on molecular systems, and that he knows of no
similar consortia in the United States.
Molecular nanotechnology will raise numerous policy
issues. In many areas, years of consideration will be
necessary before wise policies can be formulated. This
section provides only a brief, preliminary survey of a
few issues of particular prominence. Research in
molecular nanotechnology will by its nature pose no
special risks so long as it remains unable to make large
quantities of product. In its early phases, it will most
closely resemble a branch of laboratory chemistry, and
its chief product will be information. Later, when
large-scale applications become possible, major
regulatory issues will arise. Further work will be
necessary to identify these issues, but because molecular
manufacturing can be used to produce high-performance
systems of many kinds, these issues will surely include
arms control. Because the Unites States has no clear lead
in this technology and because large-scale commercial
applications are still distant, international cooperation
in research may be desirable. Further, because potential
long-term applications include weapon systems, a failure
to establish cooperative international efforts could lead
to dangerous outcomes. These considerations suggest the
desirability of a development program involving
international cooperation centering on shared global
concerns with health and the environment. One possible
vehicle for this might be an expanded version of the
existing Human Frontier Science Program. It seems that no
special regulatory issues will arise for some time, but
this time should be used to gain an understanding of the
issues that will emerge as the technology matures.
Cooperative development can provide a basis for eventual
international controls, for example, of the use of
molecular manufacturing in arms production.
Evaluating molecular nanotechnology
The U.S. scientific community has reached no consensus
regarding the prospects for molecular nanotechnology;
indeed, these ideas have stirred heated controversy. A
recent OTA study could identify no published scientific
arguments on the other side (vague and unscientific
objections have been common), but it would be unwise for
a decision maker to advocate a major commitment of
resources to molecular nanotechnology without further
study and evaluation.
This autumn, the first quantitative, detailed,
book-length analysis of molecular manufacturing will be
published (Nanosystems: Molecular Machinery,
Manufacturing, and Computation, Wiley/Interscience).
This work lays out the fundamental principles of
molecular machinery and describes how molecular machines
can collect, orient, process, and assemble molecules with
high efficiency and reliability. If there is a major
error or omission in this analysis of molecular
manufacturing, it should be possible for a critic to
describe the difficulty in quantitative, scientific
terms. Experience shows, however, that the scientific
community does not move swiftly to evaluate
interdisciplinary engineering proposals. No single
discipline sees it as a responsibility, and most
scientists see the work as a distraction from winning
their next grant. If these concepts are to be evaluated
soon, and well enough to enable decision makers can
choose with confidence, deliberate action seems
necessary. A natural choice would be to commission a
study of molecular manufacturing, setting the objective
of evaluating its scientific and technological
feasibility by seeking specific, scientific criticisms
and responses from appropriate researchers. A study of
this sort could provide a basis for decisions and could
stimulate further debate and analysis that would provide
a still better basis for decisions. The Office of
Technology Assessment may be an appropriate agency to
conduct this initial study.
Conclusion
Molecular nanotechnology promises a fundamental
revolution in the way we make things, and in what we can
make. By bringing precise control to the molecular level
- resembling the control found in living organisms--it
can serve as a basis for manufacturing processes cleaner,
more productive, and more efficient than those known
today. Like green plants, it can produce inexpensive
solar collectors and other useful products while removing
carbon dioxide from the atmosphere. Because it will work
with the basic building blocks of matter, its
applications are extraordinarily broad: they include
improved materials and computers. Early applications will
include scientific and medical instruments. Pure science
has prepared the ground for molecular nanotechnology: it
is now time to build. Initial goals include the
development of better techniques for positioning
molecules and for building molecular machines. Research
in chemistry, biochemistry, and proximal probe microscopy
can all make substantial contributions. Computational
simulation has begun to show in detail what can be built
and how it will work. Design, simulation, and laboratory
research can all benefit from support targeted on
genuinely relevant research. Progress will depend largely
on the willingness of molecular scientists to solve
problems that contribute to engineering objectives.
Research leading toward molecular nanotechnology is
accelerating worldwide. Focused research is perhaps
strongest in Japan. Although large-scale capabilities
(and the need for regulation) are still years away, it is
not too early to consider the consequences of success and
to build the framework of international cooperation that
will be necessary in order to manage those consequences.
The preceding paragraphs assume that the analysis
supporting the case for molecular manufacturing is
essentially correct, but there is as yet no consensus on
this. The evaluation of interdisciplinary proposals is
slow in the absence of a deliberate effort. It is time to
make that deliberate effort, to evaluate the evidence and
set research priorities accordingly. If we merely wait
and see, we will accomplish more waiting than seeing.
Economic competitiveness and the health of the global
environment may depend on timely action.
Assembled (a), cross sectional (b), and exploded (c)
views of a design for a planetary gear system containing
11 moving parts and 3,557 thousand atoms. Rotation of the
inner shaft forces a rolling motion of the nine
surrounding gears, driving rotation of the larger shaft
(to the right) at a lower speed. A molecular machine
component of this sort could not be made with existing
chemical techniques, but could be part of a mechanical
system made using molecular manufacturing. This design is
the result of a collaboration between Dr. K. Eric Drexler
of the Institute for Molecular Manufacturing and Dr.
Ralph Merkle of the Xerox Palo Alto Research Center,
using molecular simulation software developed by
Molecular Simulations Inc.
From Foresight
Update 14, a newsletter on nanotechnology
published by the Foresight Institute, PO Box 61058, Palo
Alto, CA 94306, USA; foresight@foresight.org.
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