A publication of the Foresight Institute
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
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
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:
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
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 $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.
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
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 $185 million over the next ten 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 U.S., 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.
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
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:
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
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.
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
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.
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 U.S. 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 of 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.
Assembled (a), cross sectional (b), and exploded (c) views of a design for a planetary gear system containing 11 moving parts and 3,557 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.
The U.S. 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 U.S. contains a similar display, because no such set of books exists in the English language.
MITI's commitment of $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 U.S.) 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 U.S., and is seen as 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 U.S.
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 U.S. 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.
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 to 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.
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 world wide. 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.
The term nanotechnology is here used to refer to an anticipated technology giving thorough control of the structure of matter at the molecular level. This involves molecular manufacturing, in which materials and products are fabricated by the precise positioning of molecules in accord with explicit engineering design.
From Foresight Update 14, originally published 15 July 1992.
Foresight thanks Dave Kilbridge for converting Update 14 to html for this web page.