Elizabeth Gardner reports on "Micro- and
The blending of microtechnology with nanotechnology took
another leap forward in Davos, Switzerland, in late September, at
"Micro- and Nano-Engineering '94." If this meeting
doesn't ring a bell, it's because for the first nineteen years of
its existence, it was known as "Microcircuit
Engineering," and it convened annually in various parts of
Europe so that people involved with microchips and other
micro-things could get together and discuss lithography: optical,
x-ray, electron beam, and ion beam.
This, though, was nano-year. The meeting planners decided to take
official notice of probe technologies like the scanning tunneling
microscope and the atomic force microscope. It's no accident: not
only has there been a lot more probe work around lately, but
conference chairman Peter Vettiger is a researcher at IBM's Zurich laboratory,
under the same roof as Heinrich
Rohrer, who shared a Nobel Prize in 1986 for inventing the
STM. He enlisted Rohrer (a newcomer to this meeting) to give the
keynote speech, and the planning committee added tracks on
"Atomic and Nanoscale Engineering" and "Nanoscale
Fabrication and Devices." As a result, Vettiger says, the
number of meeting attendees jumped from 200 last year to 340 this
year, and the number of submitted papers zoomed from 100 to 172.
Participants included not only Europeans but large contingents
from the U.S. and Japan.
Rohrer's keynote touched on topics familiar to nanotechnology,
though new to some attendees. He predicted that
"miniaturization," as such, will reach its limits by
2010, and even now is converging with the idea of building
molecular machines. The trick will be to make industry understand
that there's a new standard. "A farmer 150 years ago would
have said that the micrometer had no consequence for him,"
Rohrer said. "The nanometer has no consequence for many
things today, but it will become the new standard." And it's
no good asking industry what it wants, he added. "The
customer can only want what he thinks is possible. The far
outreaching changes must be made by scientists."
The big news of the conference came right out of one of its usual
interests: the creation of ever smaller circuits. Stanford
University applied physics professor Calvin
Quate, a last-minute addition to the plenary session
speakers' roster, described making a working transistor with an
electrode 0.2 micron wide, using an AFM as an etching tool on a
surface of amorphous silicon. Conference attendees agreed that
this was the first time they had heard of anyone using an AFM to
make a working device. Even though other researchers have
achieved the same dimensions with standard lithographies, those
techniques are bumping up against their limits, while the AFM can
potentially make transistors a tenth, or even a hundredth, the
size of the ones produced by Quate's team. And since drawing them
one at a time is hardly a manufacturer's dream, Quate is
experimenting with parallel arrays of five AFM tips working
simultaneously. If he's successful with five, he says, why not
IBM's Watson Research Center presented its new electron beam
microcolumn, just a few centimeters long and a few millimeters
wide, which could be incorporated into a tiny scanning electron
microscope. The columns could also be used for e-beam lithography
in the types of manufacturing arrays envisioned by Quate. Batch
manufacture makes them cheap, "almost a throw-away part of
the equipment," said IBM researcher T.H.P. Chang, though
they have the same current and resolution as a full-size e-beam
Several groups presented work from Japan. A team from Mitsubishi
used an STM to manipulate individual C60 molecules
into a row. A team from Hitachi used an AFM to record patterns of
gold dots ranging from 10 to 100 nanometers in diameter on a
silicon dioxide surface, and then used the same cantilevered tip
to read back the pattern. The technique could potentially be used
for high-density data recording. Perhaps most significant, the
process is carried out in air rather than under vacuum, making it
easier to use for practical applications.
And a sign of things to come: Henry Smith, who
holds a chair in electrical engineering at MIT and is not only a
pioneer in x-ray lithography but also a noted gadfly in the
microengineering field, was spotted during one session absorbed
in a textbook on molecular biology. Quizzed about this later, he
said he was taking a course and had to study for the exam. His
eventual goal? To form a research group to create and study
self-organizing systems. He's recently relocated his e-mail
a fileserver named "nano."
Integrated Chemical Systems: a Chemical Approach to
by Allen J. Bard
(Wiley Interscience, 1994, hardcover, 324 pp, $49.95)
To chemists, this book's greatest value will be as an
introduction to thinking about using chemistry to build devices.
To non-chemists, it has additional value as a signal: it was
written by the Editor in Chief of the Journal of the
American Chemistry Society, one of the most (perhaps the
most) prestigious chemistry journals. Combine this with the quotation from Nobel
Laureate chemist Roald Hoffman elsewhere in this issue, and the
conclusion is clear: Key chemists have adopted molecular
nanotechnology as a research objective.
Prof. Bard, an electrochemist at University of Texas at Austin,
based the book on a set of lectures given at Cornell in 1987,
then updated the material through late 1992, just before Nanosystems
was published. Chapters 4-6 discuss electrochemistry, while
chapters 1, 2, and 7 are more general, with chapter 2 leading off
with a quotation from Engines
In the concluding chapter, the author looks toward possible
future applications of integrated chemical systems: sensors,
electronic devices, and advanced or "intelligent"
materials. "Homes might be constructed of plastic lumber
with ceramic roofs and electrochromic windows. Cars can be
assembled of composites stronger than steel but 10 times lighter,
with ceramic engines operating at high temperatures without a
radiator. Artificial muscles will be made of polymers whose
dimensions can be varied electrically."
The author concludes, "The tools for the construction and
characterization of integrated chemical systems are now
available." For the non-chemists among us, this book can be
used as a gift for any skeptical chemist friends who are still
having difficulty with the concept of constructing materials and
devices with molecular precision. Molecular precision is what
chemistry is all about, and leading chemists are sending a clear
message to their colleagues: Let's get moving.
understanding of the impact of space on the future, and of future
technologies on space. Foresight Institute welcomes this because
in its opinion all organizations looking at long-term
implications and long-term planning will soon need to take
nanotechnology into account, even in short-term recommendations.
NSS is leading the way in this endeavor.
Excerpts: Executive Summary
by Tihamer Toth-Fejel and Tom McKendree
The National Space Society believes that developing molecular
nanotechnology will advance the exploration and settlement of
space. Present manufacturing capability limits the performance,
reliability, and affordability of space systems, but the
bottom-up approach of molecular nanotechnology has the potential
to produce space hardware with tremendous improvement in
performance and reliability at substantially lower cost.
Since the settlement of space is not a near-term endeavour, it
would be a grave mistake to consider only the short term
applications of molecular nanotechnology to space, though there
may be a few...For example, improved scanning probes similar to
Scanning Tunneling Microscopes (STM) could give researchers a
powerful, general technique for characterizing the atomic
structure of molecular objects. Applied to engineered materials,
improved probe microscopy could be valuable in discovering and
designing stronger materials, faster and smaller electronics, and
exotic chemicals with unique properties. These incremental
improvements would offer the possibility of small improvements in
capability across the broad spectrum of space activities,
ensuring mission completion, prolonging spacecraft life, and
fostering the safety of human crews.
As nanosystems used in research are constructed and
commercialized, they will move from gathering basic science
knowledge in laboratories to collecting data in engineering
applications. The first applications would be those in which the
relatively high cost and limited capabilities of these first
generation devices will still provide significant improvements in
overall system capability to justify the costs. Since sensors and
actuators could be significantly reduced in size and mass,
planetary probes and other space-based applications would
probably one of the first beneficiaries of these nanosystems.
In the medium term, the nanosystem devices would be involved in
the manufacturing process. Products might include bulk structures
such as spacecraft components made of a diamond-titanium
composite. The theoretical strength-to-density ratio of matter is
about 75 times that currently achieved by aerospace aluminum
alloys...The bottom-up approach promises to virtually
eliminate...defects, enabling the fabrication of stronger
materials that could improve reliability and increase payload
capacity...The overall effect would be that success rates for a
wide variety of space missions would increase at lowered cost.
Since the settlement of space is a long-term enterprise, the
long-term benefits of molecular nanotechnology are the most
relevant, as they are considerable...especially the ability to
bootstrap production via self-replicating universal assemblers.
This capability would probably lower manufacturing costs by many
magnitudes, down to the order of $1 per kilogram. It would become
possible to build tapered tethers from geosynchronous orbit to
the ground, and to build human-rated SSTO vehicles with a dry
mass around sixty kilograms. Such capabilities should make
possible inexpensive access to space. Mature nanosystems might
make possible affordable and robust closed environment
life-support systems that could take advantage of in-situ
resources, such as asteroidal metals and cometary organics. Such
a capability would potentially enable many people to affordably
live in space. Tiny computers, sensors and actuators, trivially
cheap on a per-unit basis, may allow things like smart walls to
automatically repair micrometeorite damage, unobtrusive space
suits, and terraforming tools. By providing instrumentation that
allows the development of medical knowledge at the molecular
level, advanced nanosystems might enable in vivo repair of
cellular damage, mitigating the dangers of ionizing cosmic
There is a fear that spending money on molecular nanotechnology
will reduce the amount of money spent on space development, since
research funding is sometimes perceived as a zero sum game.
First, decision theory and experience show that achieving large
projects of significant technological complexity (e.g., the
settlement of space) require a diversification of effort. It is
especially important to have a diversified portfolio of
approaches so that unforeseen dead ends can be circumvented
without delay. In this case, space development can benefit
significantly by investing a limited amount of effort in low
cost, high payoff avenues such as molecular nanotechnology.
Second, the amount of money needed at this stage of molecular
nanotechnology development is very small compared to the average
NASA space project...
In conclusion, the National Space Society believes that since the
settlement of space is a long-range project that will benefit the
entire human race, the serious development of long-range
technologies such as molecular nanotechnology must be supported.
Extra-special long-term thanks go to Dr. Russ Mills, long-time
technical columnist for Foresight, who is taking a sabbatical
from his writing duties. Russ's column has been a favorite of
Foresight members since Update 3 in 1988, and his ability
to take diverse technical articles and turn them into a coherent
overview of progress toward nanotechnology is extraordinary. In
Foresight's early years, Russ Mills and Dave Kilbridge did the
layout of the Update as well. We wish them the best of
luck in their business venture.
technology. Tel 212-248-0327; fax 212-248-0245; email firstname.lastname@example.org.
4th Foresight Conference on Molecular Nanotechnology &
Molecular Manufacturing, Nov. 8-11, 1995, Palo Alto. Enabling
science and technologies, molecular components, systems design,
R&D strategies. Foresight Institute, tel 415-917-1122, fax
415-917-1123, email email@example.com,
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