Nanotechnology: From Feynman to the
Grand Challenge of Molecular Manufacturing CHRISTINE L. PETERSON
The
term
nanotechnology has
come to have two primary meanings: 1) new science and technology that
takes
advantage of properties operating at the nanoscale, and 2) building
with atomic
precision through the use of molecular machine systems. The first
meaning
refers to developments occurring today; the second to an ambitious
technological goal at least a decade off. These radically different
meanings
are making coherent discussion of public investment policy and societal
implications very difficult.
I will
distinguish them by
referring to the first as near-term nanotechnology and the second as
molecular
machine systems, or molecular nanotechnology (MNT), also termed
molecular
manufacturing. This paper will attempt to sketch the history of the
field
overall, the confusion that has arisen between the various types of
nanotechnology, the politics of U.S. funding, and prospects for
broadening
future R&D to put greater emphasis on the goal of building with
atomic
precision. Although I strive for accuracy and fairness, in appraising
my
argument the reader should know that the Foresight Institute, of which
I am an
officer, is one of the main partisans in the controversy under
discussion. The
Feynman Goal
Perhaps
surprisingly, it was
the second, futuristic meaning that was introduced first. The basic
concept was
outlined by Nobel Prize-winning physicist Richard Feynman in 1959, when
he said
“The principles of physics, as far as I can
see, do
not speak against the possibility of maneuvering things atom by atom.
It is not
an attempt to violate any laws; it is something, in principle, that can
be
done; but in practice, it has not been done because we are too big”
[1].
He described building with atomic precision, and even sketched out a
pathway
involving a series of increasingly smaller machines. He explained, “if
we go
down far enough, all of our devices can be mass produced so that they
are
absolutely perfect copies of one another.” These assertions were
sufficiently
new to his audience of physicists that some in the audience laughed,
under the
impression that he was joking [2], [3].
Although he
did not use the
term, it is clear that Feynman was pointing toward what is today termed
molecular manufacturing, a goal of using systems of molecular machines
to build
with precision at the atomic level subsequently explored by K. Eric
Drexler in
journal articles beginning in 1981 [4], [5] and in the textbook Nanosystems in 1992 [6]. Thinking in
terms of molecular machines leads to a fundamental change of viewpoint:
Rather
than taking physical matter as a given, with an uncontrolled bonding
structure
having to be carved away into smaller pieces of approximately the
correct
composition and shape (the “top-down” method of product construction),
matter
can be perceived as something to be manipulated far more precisely,
building
large products from the “bottom-up” [9]. If this could be actualized,
it
potentially would affect every physical object from computers to the
human
body, leading an early observer to comment that it “could bring more
change
than all that had come about since near-medieval times” [10]. To
envision
this proposed
technology, picture a conveyor belt and assembly line such as one would
find in
a factory today — but at the nanoscale. Molecular
manufacturing would
combine the chemical action of reactive molecules with the atomically
precise
three-dimensional positioning seen in contemporary scanning probes.
Building
macroscale products with this technology of course would require
massive
parallelism. Manufacturing performed in this manner would maintain
control over
all materials being utilized, leaving little excuse for dumping excess
molecules into the air or water — and thereby substantially reducing
chemical
pollution [11]. One can also envision nanoscale robotic systems for
medical
applications. Assuming that the manufacturing processes could be
performed
cheaply and in a decentralized manner, the implications for alleviating
poverty
are inescapable. [12], [13]. Space transportation and development
likewise
would benefit, perhaps enormously [8]. On the
other
hand, the
history of technology reveals that any powerful new technology can be
used for
harmful as well as beneficial purposes, and MNT advocates began early
on to
explore potential military uses and accident scenarios [8], [12], [13].
A
non-profit organization, Foresight Institute, was formed in 1986 to
educate the
technical community and general public on these and other issues, with
the
intention of “preparing for nanotechnology.”
Inspired in
part by the mid-1970s’
Asilomar guidelines developed by biotechnologists seeking to conduct
their
early work in ways both safe and publicly acceptable, Foresight in 1999
published draft guidelines for safe development of MNT, including
specific
recommendations for environmental protection such as requiring
artificial
rather than natural fuel sources [16], [17]. (See Table I.) Researchers
from many fields
began to re-label and adapt their work as “nanotechnology,” partly to
make
clear the interconnections, and partly to jump on what was coming to be
a
funding bandwagon. They were of course aware that the word had a
radical-sounding
connotation; as one of the planners of the NNI, Hewlett-Packard
researcher Stan
Williams, stated, he “didn’t like the word nanotechnology” [18].
Nevertheless,
the term had the advantage of capitalizing on a decade’s publicity
regarding potential
medical and other benefits, enhancing the likelihood of administration
support
and At
U.S.
congressional
hearings held in June 1999 to discuss establishing a major new
nanotechnology
R&D program, supporters of molecular manufacturing were represented
by
computational nanotechnologist Ralph Merkle, who described potential
MNT
benefits and argued “the benefits will be pervasive across companies
and the
economy; few if any companies will have the resources to pursue this
alone; and
development will take many years…. We know it's possible. We know it's
valuable. We should do it” [19]. It seems unlikely that MNT advocate
Merkle
would have been given such a central role (as one of four invited to
testify)
if the new program’s proponents had not intended to send Congress the
message
that MNT research would be included in the expanded initiative [20]. A
1999 NNI
promotional brochure likewise described and seemingly endorsed
“Feynman’s
vision of total nanoscale control,” terming it “the original
nanotechnology
vision” [21]. Another NNI document explained, “the essence of
nanotechnology is
the ability to work at the molecular level, atom by atom, to create
large
structures with fundamentally new molecular organization” [22]. In
January
2000, President
Clinton went to the California Institute of Technology to announce the
new U.S.
National Nanotechnology Initiative (NNI), initially to be funded at a
level of
$500 million. Although MNT was not explicitly funded,
Controversy Arises In April
2000, however, a
serious public relations problem arose when respected
technologist-entrepreneur
Bill Joy published a long essay in Wired
magazine reviewing potential downsides of various technologies,
including MNT
(referred to as “nanotechnology”), and called for “relinquishment” of
pathways
he considered too dangerous [23]. As then-Chief Scientist of Sun
Microsystems, Joy’s
ideas provoked widespread discussion. Although his proposal for
relinquishment
was not immediately taken up by any major activist groups, the original
NNI
program designers nevertheless became concerned that discussion of MNT
risks could
possibly impact federal funding for all nanotechnology [24].
Two
responses were possible: 1) acknowledge
the power of the technology and openly discuss ways to avoid potential
problems, or 2) deny that the potential problem exists. While Foresight
had
long advocated the first path, NNI leadership opted for the second.
Richard
Smalley, who in 1993 “to explain to people what I thought the future
was…had
given the board of governors here at Rice…copies of some of Eric’s
books” [2],
published a critique of MNT in Scientific
American in September 2001. Now partially disagreeing with Feynman,
he
said, “There’s plenty of room at the bottom. But there’s not that much room…To put every atom in its
place — the vision articulated by some nanotechnologists — would
require magic
fingers.” He suggested that steric issues (“fat fingers”) and molecular
adherence problems (“sticky fingers”) would render the MNT goal
impossible
[25]. Chemist George Whitesides, writing in the same issue of Scientific American, raised technical
objections to MNT ranging from friction, to power, to information
storage and
processing. Responding to the assertions, Drexler and colleagues
pointed to
experiments contradicting some of the alleged constraints, suggested
that MNT
theory had been partly misinterpreted, and argued that some of the
Smalley-Whiteside problems were not fundamental ones but more like
design
constraints to be overcome by appropriate engineering [26], [27].
From
the viewpoint of the
Foresight Institute – admittedly a partisan one – the debate from that
time on
lacked the character one would hope to find in serious intellectual
disputes
with substantial public consequences. The critics of MNT did not tackle
the
points of disagreement systematically, using whatever logic and
evidence would
have been appropriate. Instead, the disagreement was conducted in terms
closer
to what one often finds in political campaigns. For example, at a joint
EU/NSF
workshop in early 2002, rather than responding to technical and policy
concerns
expressed about potential problems with nanomachinery, NNI director
Mihail Roco
attempted to shut down inquiry by decreeing that “None of this exists…
this is
only science fiction…these aspects stay outside the development of
nanotechnology as we intend it” [29],[30]. At a subsequent industry
conference,
the NNI director projected that what he termed fourth-generation
nanotechnology, “molecular nanosystems,” would probably arrive by about
2020;
but he made no mention of that term’s long association with molecular
manufacturing [31]. “People following the NNI (in 2002) knew where it
was
headed and that it tried to avoid MNT-related topics” [32].
Foresight
and the Institute
for Molecular Manufacturing sought to counteract this trend in various
ways,
including, at the invitation from the White House Office of Science and
Technology Policy, proposing recommendations for “Balancing the
National
Nanotechnology Initiative’s R&D Portfolio” [33]. The situation grew
more
interesting yet, however, when well-known author Michael Crichton
published the
nanotech thriller-horror novel Prey in November, 2002 [28].
Ethics
scholars began to weigh in, as did the ETC Group, both calling for new
processes for public participation, and the latter calling as well for
a
moratorium on some types of nanotechnology commercialization.
Both
public participation
advocates and MNT advocates were well represented at hearings of the
House
Science Committee in early 2003 [34], [35], when the NNI was being
converted to
a more permanent program, and the committee’s draft legislation
effectively
addressed both goals. The public participation provision was weakened
prior to
passage, however, and MNT opponents successfully lobbied for a
last-minute
wording change, replacing the requirement for a MNT feasibility study
with the
generic term “molecular self-assembly,” which may prove vague enough to
allow
NNI leadership to do or not do pretty much what they prefer [36].
At
about the same time
(December 2003), at least some of the attendees at a meeting of the
National
Science Foundation on societal implications of nanotechnology reported
that
they tacitly understood that discussion of MNT was verboten for anyone
who
wanted to retain credibility there [38], [39]. That same month, the
cover of
the leading chemistry weekly, Chemical
& Engineering News, featured a vivid illustration of molecular
manufacturing [40], and the issue included a debate between Smalley and
Drexler. The former no longer asserted that MNT would require “magic
fingers,”
but adduced other technical and metaphorical arguments, which Drexler
of course
attempted to rebut (successfully, in my opinion). Most readers probably
found
that the exchange ended rather unsatisfactorily, but it did have the
virtue of
making the controversy more visible [41], [42]. Policy journals have
begun to
cover nanotechnology politics and policy, including the present
publication and
the Bulletin of Science, Technology
& Society
[43]. Deliberately
Moving Toward
MNT, or Not? We
are now at a crossroads
with regard to MNT technology. A certain fraction of researchers in the
physical sciences and engineering assume that, since molecular machine
systems
exist (and are powerful) in nature, the proposal that artificial ones
could
someday be built, and be even more powerful, is rather obvious. Many of
them
assume that the NNI is working toward this goal, a perception that,
while
mistaken, is understandable because, as this is written, an internet
search on
the term “nanotechnology” indicates that the MNT view of nanotechnology
still
dominates the top ten sites, despite billions of dollars of NNI
spending on
nearer-term work. Even the harshest critics of MNT admit that the
concepts
“even in the scientific arena… tend to dominate discourse around the
possibilities of nanotechnology” [44].
Given
the current
controversy, most of those potentially receiving government funding
avoid
expressing a definite opinion; when put on the spot, however, few are
willing
to say that MNT is impossible [45], [46]. Stanford physicist Stephen
Chu has
estimated fifty years for the more difficult applications [47], not an
implausible estimate if one assumes no coherent effort. Given the
military and
economic advantages expected to accrue to the country reaching real MNT
capabilities first, however, such a long delay seems unlikely. Ray
Kurzweil has
estimated thirty years [35], Ralph Merkle says “probably not many
decades”
[48], and the Center for Responsible Nanotechnology offers the low
estimate — “less
than twenty years from now — possibly less than ten” [49].
Despite
the lack of a focused program, a significant amount of research now in
progress
is contributing to MNT infrastructure in fields ranging from molecular
self-assembly, scanning probes, and organic synthesis, to the
atomically
precise areas of nanoparticle and nanofiber work. (See [43] for a
partial
summary.) Some of this was covered at the first Symposium on Molecular
Machines
in October, 2004.
Eventually,
I anticipate
that the U.S. will adopt as its nanotechnology Grand Challenge the goal
foreshadowed by Feynman in 1959 and described by nanotech venture
capitalist
Steve Jurvetson: “Whether conceptualized as a universal assembler, a
nanoforge,
or a matter compiler, I think the “moon-shot” goal for 2025 should be
the
realization of the digital control of matter, and all of the ancillary
industries, capabilities, and learning that would engender” [50]. A
July 2004
report on nanotechnology from the
Whatever
the prospects for
a civilian program, a military one seems close to inevitable. Warfare
has
already moved into the nanoscale in the sense that bioweapons are
systems of
molecular machines that attack other biological systems. For defense,
one would
like to have tougher, stronger, more flexible molecular machine
systems, and
this is what MNT should be able to provide. Given this need, it seems
only a
matter of time before a one or more governments launch military R&D
MNT
programs.
Such
an effort will not
necessarily start first in the
My
hope is that inquiry,
deliberation, and policy attention soon can move beyond the relatively
unproductive controversy between near-term and longer-term
nanotechnology. We
need to be looking at 1) how to manage the intellectual property
resulting from
publicly-funded MNT research to maximize public benefit, and 2) how to
deliver
the economic and environmental advantages of molecular manufacturing
without
also distributing the ability to construct powerful new weapons. Though
their
ranks need to be expanded greatly, a number of scholars and public
intellectuals in fact are analyzing such issues. Among these are Glenn
H.
Reynolds, author of the first law review article on nanotechnology,
continues
to develop policy recommendations [51]-[53]. Lawrence Lessig, a law
professor
at Stanford, is carrying his groundbreaking intellectual property work
called
“Creative Commons” into the science arena, with plans to apply it to
nanotechnology [54]. And Chris Phoenix at the Center for Responsible
Nanotechnology
is working to outline gaps in our knowledge of molecular manufacturing
and what
studies are needed to attempt to fill them [55]. One
of the most pressing
questions actually may recently have been settled – the question of
whether
continuing down the MNT track would necessarily mean creating risks of
autonomous self-replicating nanomachines (as depicted, or caricatured)
in Prey.
It now seems clear that there is no need for a nanomachine able to
duplicate
itself as biological systems do, because MNT machinery can be made on
an
assembly line just as ordinary “macro” machines are. Self-replication
would be
a very difficult feature to implement, in any case, with no obvious
economic
advantage, and with several types of perceived and actual risks. Hence,
many
MNT advocates now believe that “the construction of anything resembling
a
dangerous self-replicating nanomachine can and should be prohibited”
[58].
Another
bugaboo that should
be politely dismissed is the notion that MNT advocates believe their
technology
will be able to solve all human problems. Given that some of these,
such as the
desire to take others’ goods and dominate one’s neighbors, seem to be
deeply
embedded in a fraction of human personalities, on reflection no one
could take
seriously the notion of a general technological fix for social
problems. However,
by developing public policies in advance, we should be able to
substantially
reduce the drawbacks of MNT technology, increase benefits – especially
for the
world’s have-nots, and limit MNT use in coercion. We can start now by
working
toward intellectual property reform, including more inexpensive,
collaborative
“open source” technologies, and weapons proliferation-reduction systems
featuring increased openness [63]. NMT Unstoppable In
sum, MNT advocates
believe that the technology 1) is coming, 2) has large potential
benefits to
medicine, the environment, transportation, energy, and virtually every
area of
physical technology, 3) has large potential abuses including by
militaries, and
4) cannot be stopped. MNT critics disagree. Humanity will not know for
some
time which side proves correct, yet must decide now how to respond to
the
controversy. One way to put the choice that partly sidesteps the
disagreement
between MNT advocates and critics is this: Would an intelligent
civilization
rather risk wasting effort in preparing to cope wisely with MNT (and
then find
out the technology is impossible)? Or would the civilization be better
off
hoping that MNT is impossible (and then being caught unprepared if it
actually
emerges)? The international technical community, including professional
societies such as IEEE with its social and ethical emphasis, can play
an
important role in helping the world to make this choice. Author Information The author is
Vice President
of Foresight Institute, References
[1] R.
Feynman, “There’s
Plenty of room at the bottom: An invitation to enter a new field of
physics,” Engineering and Science, Feb. 1960,
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“Science on the
surface,” Lawrence Berkeley Lab Res. Rev.,
Spr. 1996,
http://www.lbl.gov/Science-Articles/Research-Review/Magazine/1996/sci1.html. [4] K.E.
Drexler, “Molecular engineering:
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