Foresight Update 30
Page 4
A publication of the Foresight Institute
 Media
Watch.30
Not-Quite-Nano Breakthroughs
As awareness of the concept of molecular technology spreads
through the scientific and lay communities, the word
"nanotechnology" becomes ever more fashionable. And,
alas, it becomes ever more frequently applied to something other
than its original meaning. The trend reached full flower recently
with a story in Nature (June 5, 1997)—and
considerable related coverage in general media—proclaiming
"the first nanomachine," a bioelectronic device
developed at the Australian Membrane and Biotechnology Research
Institute (AMBRInstitute). See this issue's "Recent Progress" and
"WebWatch"
columns for more details.
It was a nice piece of work they did Down Under, but a
"nanomachine" it isn't. "The device harnesses the
self-assembly dynamics of the lipid membrane, and thus provides
access to the sensitivity of nanotechnology using only bench
level chemistry," its designers said. This is a significant
development, but not directly on the path toward programmable
molecular assembly.
Associated Press carried another story that
further illustrates the confusion now surrounding the term
"nanotechnology. In Ithaca, NY, researchers
at Cornell University carved a guitar out of crystalline
silicon to demonstrate the possibilities of building
electromechanical devices at the nanometric level. Coming just
before the 20th anniversary of Elvis Presley's death, the reports
of a "nanoguitar" were well timed, creating the
possibility of Nano-Elvis sightings.
"Building dimensions in nanometers requires a new approach
using high-voltage electron beam lithography. The teeny-weeny
musical instrument, dubbed the nanoguitar, was sculpted out of
single crystal silicon," AP reported. "The strings are
each about 50 nanometers wide—the width of about 100 atoms.
They could be plucked using the tip of an atomic force
microscope."
"I know we can go smaller than this," Cornell Applied
and Engineering Physics Professor Harold Craighead is quoted as
saying. "The question is, how small can we go and still have
dependable and measurable mechanical properties. We are nearing
the technological limit where it gets harder to get smaller than
this."
These examples follow a pattern that Foresight Institute has been
anticipating for several years: As the scientific underpinnings
of molecular nanotechnology become better understood within the
science community, it becomes more professionally acceptable for
researchers to position themselves as
"nanotechnologists." A first-order consequence will be
more widespread confusion about just what constitutes
"nanotechnology." Our recommendation: whenever you talk
to someone about the subject, take the time to provide your
definition of the term, and distinguish "molecular
nanotechnology" from the top-down technologies which
sometimes march under the same flag.
Foresight also expects increasing attention to the economic and
social issues which the realization of molecular nanotechnology
is expected to bring. Some of that discussion will embrace
Neo-Luddite arguments that nanotechnology research shouldn't be
pursued. Expect this to happen, and understand that it is part of
the process of preparing for nanotechnology, even if it isn't
always comfortable.
Report on Business Magazine, in its June 1997
magazine, extensively featured Xerox Corp. nanotechnologist Ralph Merkle in a story
entitled, "Beyond the Microchip." Author Clive Thompson
described Merkle's appearance before a conference of microchip
manufacturers last fall in which he described the expected end of
Moore's law as current microchip manufacturing techniques reach
their limits.
"If the microchip engineers want to keep increasing computer
performance, they'll need to break out of the box; find totally
new ways to create subminiature chips; write software that thinks
in radically different ways," Thompson wrote.
"Otherwise, Merkle thinks, computers won't get faster,
memory won't expand any further and software won't become more
powerful. Corporations of the future would be stuck with the
technology of the past."
"When Merkle delivered this message, the engineers stood and
cheered."
Foresight Executive Director Chris Peterson is also quoted
discussing self-assembly using chemical reactions as a means to
make smaller chips. "We're talking about designing computer
materials the way you design drugs—mixing molecules together
using chemical reactions to create devices," she is quoted
as saying. "All the major chip makers, such as Intel,
Motorola and IBM, have engineers working on this issue,"
Thompson reports.
The Stewart platform, one of several design concepts
being considered as a basis for a molecular-scale general purpose
assembler, is gaining popularity in the macro world. Fortune
Magazine's May 26 issue writes up "Five Heroes of
Manufacturing," including New Hampshire-based Hexel Corp.,
which is marketing a sophisticated but relatively low-cost
programmable machine tool whose design is based on the Stewart
platform. Two other big tool makers, Giddings & Lewis and
Ingersoll, also are bringing "hexapod" machine tools to
market, Fortune reported; two Japanese companies
plan to join the fray soon. Inventor Paul Sheldon, who helped
design Giddings & Lewis' device, has recently filed patents
for a three-axis version of the hexapod that is expected to be
simpler and cheaper to build than the six-legged type.
Macro-scale Stewart platforms suffer from a "hot foot"
ailment, Fortune reported. "Heat from motors
causes their struts to stretch a bit when the machines are at
work, which can affect the cutting head's accuracy."
Manufacturers are compensating mechanically for strut expansion.
Ralph Merkle has analyzed the positional uncertainty of the tip
of a simple molecular Stewart platform in the face of thermal
noise, and concluded that the Stewart platform performs very well
in this respect. Drexler discusses the design concept in Nanosystems.
In the world of entertainment, the nanotechnology meme spreads
rapidly. Electronic Gaming Monthly reported in April
that Activision has been filming action movie mega-star Bruce
Willis (Die Hard, etc.) for the lead role in a new interactive
computer game called Apocalypse. "Willis plays Trey, a
nanotechnologist who recruits you in his battle against a false
prophet named the Reverend. Unfortunately, the Reverend is also a
wiz at nanotechnology, and he uses his skills to create the Four
Horsemen of the Apolcalypse...Plague, Death, War, and the
Beast." Will the threat of deliberate misuse/abuse of
nanotechnology first reach general public awareness through such
paths? We'd prefer to think otherwise, but won't be surprised if
it does. After all, science fiction novels conditioned an earlier
generation to the ideas of space flight and nuclear energy.
Web
Watch.30
Those interested in technical progress along the path toward
nanotechnology that leads through engineered proteins and
designed polymers will find a great deal of research of interest
at the Web site of The Scripps Research Institute. Only a few of
the relevant research groups are featured here (others can be
accessed from the above home page).
The research group of Prof.
Charles L. Brooks, III uses theoretical and computational
methods to study protein folding and self-assembly. One current
project made use of molecular dynamics to describe the
thermodynamics of folding of a 48-residue protein fragment
"based upon a first principles atomic level description of
the protein and solvent environment." Another computational
chemistry group with a substantial Web site on the molecular
dynamics of protein and DNA molecules is the group of Prof. David A.
Case. Highlights of their Web site include a summary
of their research, and a gallery
of structures of protein and DNA complexes determined in
solution using NMR. Various software aids for very specialized
aspects of molecular modeling can also be accessed from their
welcome page.
The more experimentally focused research of M. Reza Ghadiri,
who will be one of the instructors at the Tutorial on Critical
Enabling Technologies for Nanotechnology this November,
focuses on the design of artificial proteins and catalysts. Of
particular interest to nanotechnologists is the beautifully
illustrated page on nanotubes
produced by the self-assembly of cyclic peptides. The page
explains key features of the cyclic peptides that make
self-assembly into a designed structure feasible, and how the
properties of the nanotube can be changed according to the design
of the cyclic peptide. Other
research targeted towards the rational design of artificial
enzymes includes the use of the binding of metal ions to peptides
to control the folding of peptides into a three-helix
bundle, and the formation of a self-replicating
molecular system in which a helical peptide acts as a
structural template to guide the assembly of two constituent
fragment peptides into the proper orientation to form the
original template peptide structure.
Lawrence Berkeley National Lab's Materials Sciences Division
has made available on their Web site brief reports of research
pointing toward nanotechnology. Some offerings from their
Molecular Design Institute:
- "Catalytic
Atomic Force Microscopy", work from 1994 by P.G.
Schultz and P. McEue that used a platinum-coated AFM tip
to catalytically modify nanometer-scale patches of
surface, converting azide group to amino groups. Their
Web site contains an additional
article on this research. [See also Jeffrey Soreff's report in
Update 22.]
- "First
Nanotubes Made of Boron Nitride" reports work
from 1995 by Alex Zettl, Marvin Cohen and Steven Louie
resulting in the synthesis of nanotubes greater than 200
nm long and 6 to 8 nm outer diameter, composed of
hexagonal arrays of boron and nitrogen atoms, much as
carbon nanotubes are composed of hexagonal arrays of
carbon atoms, but with more uniform structural and
electronic properties than was the case with
contemporaneous carbon nanotubes.
- "Nanocrystal
Structures Built on a DNA Scaffold" describes
the 1996 work of Paul Alivisatos and Peter Schultz in
using DNA base-pairing to position nanometer-scale gold
particles with respect to each other. They hope to
generalize this into a method of making larger, more
complex three-dimensional structures to atomic precision.
[See also Jeffrey Soreff's report in
Update 27.]
- Other relevant articles can be found in the Berkeley
Lab archives by searching for key words such as
"nanotechnology" or "protein
folding".
Functioning nanomachine described on Web
This past June a team of Australian scientists unveiled a
novel and exciting biosensor that has been billed as the world's
first functioning nanomachine. It is not a nanomechanical device
and not clearly on the road to molecular manufacturing, but
rather an electronic device, an application of nanotechnology to
a potentially huge biosensor market done by coupling biological
molecular machinery and clever chemistry to electronic
technology. A synthetic membrane adsorbed to a gold electrode
controls the passage of an electric current via ion channels that
open or close depending upon whether or not specific receptor
molecules have bound their ligands, thus creating a very elegant
and sensitive sensor for the ligand molecule. The accomplishment
was described in a paper in Nature [see this issue's
"Recent Progress"
column], and also on several Web sites. A brief description of
the device and how it works is available in a CSIRO
media release, and in an article
in the Sydney Morning Herald. A more technical
description has been made available by the Cooperative
Research Centre for Molecular Engineering and Technology at
the University of Sydney. An easy to understand but very detailed
and beautifully illustrated Web site on the project has been
presented by the Australian
Membrane and Biotechnology Research Institute. This site will
satisfy both specialists and lay readers.
Call
for Papers: Nanotechnology & Space
The Journal of the British
Interplanetary Society (JBIS) has
announced a special issue on "From Microsystems to
Nanotechnology—Applications to Spaceflight". It is
planned to cover micromechanics, microengineering, top-down and
bottom-up (i.e. molecular) nanotechnologies, and the emerging
micro-to-nano integration technologies, with a view to their
applications to space science and technology.
The goals of the special issue are (1) putting together micro-
and nanotechnologies to foster their integration toward new
concepts of nanostructuring and new products, and (2) stimulating
the applications of emerging micro-to-nano integrated components,
devices, and systems to space applications.
Research and review papers submitted to this project should deal
with the design, construction, and operation of micro- and
nano-devices and systems, such as nanosensors and microactuators,
MEMS, micro/nano integrated devices, molecular manufacturing,
molecular electronics, nanocomputers, and nanosatellites.
Papers up to about 14,000 words can be accepted; the preferred
size is 5,000-11,000 words. Authors receive 50 free offprints of
their paper. Contributions are due by October 31, 1997, and are
to be forwarded to: Dr. Salvatore Santoli, International
Nanobiological Testbed, via A. Zotti 86, I-00121 Rome, Italy.
Tel/fax +39.6.5613439, email intitsnt@uni.net. For instructions
on manuscript preparation, contact JBIS directly at fax
+44.171.820.1504.
From Foresight Update 30, originally
published 1 September 1997.
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