Nanotechnology and the Battle to Build Smaller Source: Discovery.com The smallest guitar on earth is 10 microns long, about
as big as a human white blood cell -- the perfect size for a bacterial
rock star. Each of its six silicon strings is an amazing 100 atoms
wide. Of course the "nanoguitar" isn't meant to be played; you can't
even see it without an electron microscope. It was made by researchers
at the Cornell University Nanofabrication Facility to illustrate just
how tiny mechanical devices can get. Nanotechnology is the science of
the small. Derived from the Greek word for dwarf, nano is a
one-billionth unit of measurement. So a nanometer is a billionth of a
meter, and a virus is nearly 100 nanometers across. Nanotechnology is
the term used to descr ibe a wide array of theoretical and
experimental approaches to engineering tiny machines; everything from
making smaller microchips (Intel's Pentium processor already has parts
measuring just 350 nanometers), to envisioning molecular robots that
could swi m through our bloodstream and fight disease.
People working in the field of nanotechnology today are
divided between two disciplines: those working from the "bottom up,"
mostly chemists attempting to create structure by connecting
molecules; and those working from the "top down," engineers taking ex
isting devices, such as transistors, and making them smaller.
Top-down or mechanical nanotechnology will have the
greatest impact on our everyday lives in the near future. Cornell is
one of five nanofabrication facilities in the country funded by the
National Science Foundation. Researchers from IBM, AT&T and Raythe on,
among others, utilize the $20 million worth of equipment housed there
as an incubator for projects such as the disposable medical laboratory
on a chip. This invention would allow a medical technician to place a
drop of blood on a $5 chip, measuring th e width of a dime, and
connect it to a computer that would immediately process a diagnosis.
Such a device is "no more than five years away," says Dr. Lynne
Rathbun, the program manager at Cornell.
Perhaps less immediately useful, but equally important
is the work being done by bottom-up scientists such as Nadrian Seeman,
a structural chemist at New York University. Inspired in 1980 by an
M.C. Escher drawing, Seeman used DNA to create a cube just se ven
nanometers across. Now he's making more complex and stronger
structures, such as truncated octahedrons that could be used to make
new materials. He's even built a chemical switch that could
potentially be used in a nanosized electronic device such as a
bio-computer chip.
Seeman's work is influenced by biology more than
engineering. "Biology is nanotechnology that works already," Seeman
says. Photosynthesis is, after all, a molecular-scale mechanical
operation and enzymes are essentially nanosize factories. The
challenge f or nanotechnologists is learning to control such
processes. Once they do, huge advances in everything from
microelectronics to chemical engineering will be
possible.
Take a journey with us into this tiny world, where we'll
explore the people who are working to make nanotechology a reality,
the tools they're u sing to create tiny machines and where these
advancements might take us in the future. If you have questions, we've
asked a few experts to come o nline to answer some of them.
The Pioneers:
RICHARD P. FEYNMAN
The science of building small was first introduced in
1959 by Richard P. Feynman, a Nobel Prize-winning physicist, in a
lecture titled "There's Plenty of Room at the Bottom." At that time
most scientists were thinking big about interplanetary space travel,
but Feynman awakened them to possibilities of controlling single
molecules or even atoms and creating machines with them. Nearly 40
years later, physicists, chemists, molecular biologists and computer
scientists around the world are working in nanotechnology.
RICHARD E. SMALLEY
In 1996, Richard E. Smalley received the Nobel Prize in
chemistry for discovering "Buckminster Fullerenes." Named after the
architect who invented the geodesic dome, these soccer ball-shaped
pure carbon molecules, dubbed "buckyballs," and their cylindrical
cousins "nanotubes" are likely to be the strongest substance in
existence. Nanotubes are created by vaporizing carbon with a laser and
then letting it reassamble in an inert gas such as helium. Aside from
creating super-strong polymers that could replace the graphite used in
everything from tennis racquets to airplanes, nanotubes could be used
as circuits in the nanoelectronic devices of the future. In his
lecture "Nanotechnology and the Next 50 Years," Smalley forecasts
that, with the right advances in technology, a
nanometer-sized solar cell could be built. Such devices could
potentially provide for the world's energy needs in the year 2050.
IBM's ZURICH RESEARCH LABORATORY
IBM's nanoscience project has been making steady
advances in the field since 1990, when Don Eigler used a scanning
tunneling microscope (STM) to write his employer's initials with 35
xenon atoms. In 1996, the research team, led by James K. Gimzewski,
built the world's smallest abacus, each bead having a diameter of less
than one nanometer. The finger used to move each bead is the ultrafine
tip of the STM. Most recently, the Zurich team won accolades for
squeezing carbon "buckyballs" with an electrified STM to create a
molecular amplifier.
NASA AMES' NANOTECHNOLOGY GROUP
This group was awarded the 1997 Feynman Prize for
modeling molecular gears that could be powered by a laser. The gears,
which exist only in computer designs but are physically possible,
would rotate at 100 billion turns per second. Because the devices they
take into space must be small and light, consume very little power and
be immune to cosmic radiation, nanoelectronics are vital to NASA's
long-term success.
JANE A. ALEXANDER
Jane A. Alexander founded the ULTRA nanoelectronics
program at the Defense Advanced Research Projects Agency (DARPA).
Researchers there are dedicated to developing small, low-power, fast
micro-electronic devices for next-generation information-processing
systems, or nanocomputers. Their work could be used in everything from
virtual reality displays to cruise missiles.
GEORGE WHITESIDES
George Whitesides, Harvard's Mallinckrodt Professor of
Chemistry, extends classical chemical techniques into the realms of
biology, solid-state physics and engineering for his groundbreaking
work in self-assembling chemical compounds. In 1996 he patterned
computer chip circuits just 30 nanometers wide. Whitesides' circuits
could give a single chip the ability to perform at speeds of more than
a teraflop. Today, the most powerful supercomputer, utilizing 9,000
Pentium Pro
processors, is capable of performing one teraflop, or 30 trillion
floating point operations per second.
JAMES TOUR
In 1996, James Tour, a chemistry professor at the
University of South Carolina, along with his colleagues, created the
first functioning quantum wire -- a single molecular chain that
completed a circuit between a gold lead surface and the tip of an STM.
Tour is now testing a molecular transistor that, if successfully
completed and combined with the molecular wire, would constitute a
historic advance in microelectronics.
NADRIAN C. SEEMAN
Nadrian Seeman won the 1995 Feynman prize in
nanotechnology for building cubes and more complex structures out of
synthetic DNA. Such structures could be the building blocks of
molecular mechanical devices and could also be used to create
super-resilient "smart" materials.
K. ERIC DREXLER
Many scientists disavow Eric Drexler's popular
futuristic ideas about nanotechnology, which include a $5 nose spray
containing molecular mechanisms that would stamp out influenza
viruses; the ability to rebuild ecosystems and restore endangered
species by cloning genes; and nanotechnological weapons that would
build themselves after arriving at the target undetected. Drexler and
his proponents argue that science is too often lacking in his brand of
long-view thinking and that it's better to prepare for the
possibilities in advance than to confront them when it's too late.
Drexler's work has also inspired a new genre of science fiction,
"nanopunk," which incorporates the utopian and dystopian possibilities
of nanotechnology in its plotlines. Chair of the Foresight Institute,
Drexler helps award the annual Feynman prize in nanotechnology.
RALPH C. MERKLE
Head of the Computational Nanotechnology Project at
Xerox's Parc research center in Palo Alto, Calif., Ralph Merkle works
closely with Eric Drexler on computer simulations of molecular machine
components. Specifically, a nano-robotic arm that could one day act as
a replicator -- a machine that builds itself and thus could be used to
create nearly anything from its base molecular components. Merkle is
best known for introducing a new paradigm in computer cryptography
utilizing public and private key technology.
The Tools:
Although micromechanical and nanoelectronic devices get
cheaper and faster as they get smaller, they also become prohibitively
expensive to create. One electron beam lithography system at the
Cornell University Nanofabrication Facility costs $6 million. No
surprise then that researchers are looking for better and faster
tools.
In the meantime, scientists continue to forge the
microcosmos, and their first stop is the computer terminal. Computers
are essential to the entire nanofabrication process, from modeling to
manufacturing. Scientists at NASA Ames have powerful, cutting-edge
Silicon Graphics workstations on their desks to create complex 3-D
chemical models. Many researchers simply write their own software
programs for modeling chemicals, but HyperChem 5.0 and Gaussian 94 are
two popular off-the-shelf programs. Whatever the software, designing
the final product on a computer is the first step for any
nanoscientist.
The trick is turning a computer design into a real
object, and a very small one at that. Molecular nanotechnologists such
as Nadrian Seeman actually use a process of trial and error (sometimes
referred to as "shake and bake") to puzzle together tiny structures
like the DNA cube -- put the right chemical combinations in a beaker
and hope for success. Mechanical nanoscientists use more precise
techniquesinvolving lithography to carve precise structures into
silicon wafers.
The wafers are coated with a filmic substance and
exposed, so that an image of the pattern that will ultimately be
etched on the chip is created. Once exposed, the pattern is carved
onto the silicon wafer using reactive ion etching, a sort of
sandblasting with charged ions. But photolithography can produce
structures only as small as 250 nanometers. Smaller objects, such as
the nanoguitar, require electron-beam lithography. By drawing on the
wafer with a focused beam of electrons, scientists can pattern objects
down to 20 nanometers.
After the nanoscale object has been manufactured, it
must be studied. The electron microscope is an essential tool for any
nanotechnologist. "They're really enabling us to get down in that
nanometer playground and direct the organization of matter on that
scale," says Daniel T. Colbert, a member of Richard Smalley's research
team at Rice University. That may explain why there are so many types
of electron microscopes and still more in development.
The most important of the lot is the scanning tunneling
microscope (STM). Developed at IBM's Zurich Research Lab, the STM was
the first microscope that let scientists see individual atoms. Its
inventors, Gerd Binnig and Heinrich Rohrer, won the Nobel Prize in
physics for this microscope in 1986. The STM has a conical tip that
ends in a single atom. As the tip of the microscope moves across the
surface of an object, an atomic topographical image of the sample is
created. By
applying a bias voltage between the tip and the sample material,
scientists can inject or eject electrons -- allowing them to not only
see individual atoms, but to manipulate them. This device was used by
Don Eigler to spell "IBM" with 35 xenon atoms.
"What holds this field together is that they're all
using the same tools," says Lynn Rathbun of the Cornell
Nanofabrication Facility. "The difference is what they want to do with
them."
Futures:
Imagine a microscopic assembly line. Cubes constructed
from DNA travel along a conveyor belt made of cilia, the tiny hairs
that extend from the surface of cells. Along the way, robotic arms
insert individual molecules into the cube, each molecule building on
the last. This entire micro-manufacturing plant fits into a modern
printer, which spits out sheets of white paper. Although these sheets
weigh as much
as a regular piece of paper, each fiber is actually a one pixel-sized
robot with built-in memory equivalent to a Pentium Pro microchip. You
ask the sheet of paper for information about the earthquake of 2054,
and it flickers to life as a super high-definition television screen
showing an encyclopedic documentary on the subject.
You stop the program and search for details on how San
Francisco was rebuilt after the disaster. It tells you that a team of
architects, physicists and chemists collaborated to create a workforce
of nanocontractors, micromechanical robots programmed with
architectural designs. A handful of these tiny robots, a few billion,
were thrown on the crumbled remains of an old structure. Some of the
robots were charged with breaking down the existing raw materials --
dirt, concrete, metal -- into molecular parts. These parts were then
used by another set of nanobots to construct the walls and windows of
new buildings.
This scenario may seem more likely to appear in a
nanopunk sci-fi novel written by an author like Neal Stephenson, but
micromachines are already present in our everyday lives. A tiny
accelerometer in your automobile senses the impact of a crash and
switches on a microcircuit that activates the air bags. Hospitals use
tiny disposable microsensors to monitor a patient's blood pressure
through the intravenous line. Products such as these not only exist
today, but they're getting smaller as we speak.
In the next seven years, "Things will get wild,"
predicts Bill Spence, editor of NanoTechnology magazine. "In 15 years,
all of a sudden there will be no more automobile workers, just car
designers." In Spence's future, auto workers will be replaced by
robotic molecular assemblers.
At least one company, Zyvex, is already at work on the
molecular assembler. James R. Von Ehr II, who founded the Texas-based
facility in 1995, is the first to admit, however, that pioneering
companies often fail and that the first molecular assembler will be
incredibly difficult to build. But if built correctly, the assembler
will also be a replicator, capable of reproducing a thousand copies of
itself.
The effort will require plenty of money and even more
computing power. That's why Spence is putting together a distributed
computing project that will allow his group to model the various
designs for nanocomputers. Any desktop PC connected to the Net can
take part: a few thousand volunteers will be able to download a
screensaver that takes a fraction of each computer's power and lends
it to a central computer. When added together over time, the combined
power will equal that of a supercomputer, which will allow Spence's
group to render complex molecular models in 3-D.
It's a downright duct-tape and spit solution to the
problem compared with the work being done by most scientists, many of
whom criticize the utopian ideas espoused by Spence and his guru, Eric
Drexler. "No one knows how to make those things yet; maybe somebody
will. I don't think those guys will," says Dr. Julius Rebek, director
of the Skaggs Institute. Rebek has been experimenting with
self-assembling molecules for years and says, "Right now there's no
obvious path to what they're drawing."
Although Spence may be overoptimistic, nanotechnology is
advancing rapidly, and the next breakthrough could come from
anywhere -- several Japanese electronics corporations are busy working
on single-electron transistors that can be created with current
lithographic techniques. Wherever the breakthrough does come from, one
thing is clear: Big
things often come from small particles.
Talk to the Scientists:
Dr. Daniel Colbert, one of the scientists who works with
Nobel Prize-winning chemist Dr. Richard Smalley at the Center for
Nanoscale Science and Technology at Rice University and Dr. Richard
Tiberio and Dusti n Carr of the Cornell Nanofabrication Facility
answered some of your questions about nanotechnology. They're no
longer online with us, but you can read their responses below. Thanks
for all of your
interest and support.
The Scientists Respond
Hi!
I'm all in favor of this science at the smallest level
because this is where most of our problems begin. Is this tiny
technology being used today in the area of medicine, such as fighting
cancer? If not, is it being considered, and could you explain how i t
would be used when it comes of age? Keep up the good work and I hope
you guys have a lot of constructive accidents; as Edison once related
was how most of his discoveries came about.
Thanks, From Daniel Colbert:
Bob,
Your question gives me an opportunity to clarify an
important point about nanoscale science and technology. It's actually
been with us for a very long time. In particular, chemists and
biochemists do nanoscale science everyday. Most of this is what we at
Rice refer to as the "wet" side of nano. All of biochemistry and ce ll
biology provide examples of this. The most compelling to my mind are
enzymes: nanoscale machines that do highly specific tasks with great
efficiency. So, to answer your question directly, yes, nanotechnology
is certainly being applied in the area of medicine, as it has been for
decades, well before the current craze.
On the other hand, there are some emerging differences.
These are largely occuring where the "wet" side meets the "dry" side,
the latter not requiring water. An example might be using buckyballs
to block the active site of the HIV protease enzyme, thus interrupting
the life cycle of the virus. Or using various nanotechnologies (e.g.,
atomic force microscopy) to probe living systems. These sorts of
activities
exemplify highly active areas of research in the nano area that are
receiving much attention, and will, I think, eventually pay large
dividends.
I must also take this opportunity, since you raised it,
Bob, to disagree with you about the efficacy of the Edisonian approach
to science and engineering. While Edison did meet with significant
success, I would say it was in spite of, rather that because of his
"try everything" approach. Fortunately, science has come a long way
since then, and most researchers put considerable thought behind their
work before trying things. One reason is that without this prior
thought, the research will not be funded!
Dan Colbert
From Dustin Carr:
Hi Bob,
I don't know of any direct cancer-fighting uses, but
that does not mean there are not any. Nanotechnology is very
important, however, in the production of tools for diagnosis. One type
of tool that is being actively developed here at the Nanofabrication
Facility is a technique of DNA sequencing that can be done rapidly on
a single silicon chip. Many people are developing implanted probe
devices that can be put inside the body to monitor conditions.
Dustin
Hello, I am an undergraduate looking into wildlife with
an interest in technology associated with animals. Do you see a future
for this new technology in the outdoors for help, recovery or
monitoring of wildlife? I enjoy watching the development of tec
hnology and hope to make a contribution in my field of interest.
Ben From Daniel Colbert:
Ben,
Thanks for your question. Unfortunately, I don't know
much about this area and its application needs. I can imagine that
nano-devices might be of use in monitoring, collecting, and
transmitting data on wildlife, but I don't really have any concrete
ideas about what form this would take.
Dan Colbert
From Dustin Carr:
Ben,
I can not say that much effort is being into this right
now, but that does sound like an interesting area of research.
Hi. If nanomachines could move atoms and compounds
around to form basically anything, could we create water, oxygen,
carbon dioxide, ozone, and the other necessary gases needed for an
atmosphere? If so, wouldn't that mean we could terraform our Moon and
Mars rather quickly if the proper funding was available?
Brad
From Daniel Colbert:
Brad,
Your question gives me the opportunity to clear up some
misconceptions about nanotechnology. Nanomachines are not necessarily
required to do the kinds of thing you're talking about, if by that you
mean things like the "universal assembler." In fact, we already have a
mature, elaborate technology base to transform various m olecules into
others: it's called CHEMISTRY, and is very much at the heart of
nanotechnology. That is because both nanotech and chemistry are about
manipulating molecules to make materials that have properties we are
interested in.
So, for example, the catalyst in the catalytic converter
in your car converts toxic carbon monoxide to the more benign carbon
dioxide. Most plastic fibers, like polyurethane and polyethylene, are
produced catalytically. There are lots of examples. My p oint is that
in many senses, nanoscale science and technology is nothing new, but
rather a continuation of what's been going on for centuries: the
manipulation of matter at the smallest scale relevant to producing new
materials with desired properties. T he biggest difference may be that
we now
have wonderful techniques, such as probe microscopies and electron
microscopy, that allow us to probe these materials at the nanoscale.
Fundamentally, however, we're still doing chemistry. Bottom line:
nanotech i s not just about machines and assemblers; it's really about
gaining control over the fundamental constituents of materials --
atoms and molecules. Whether this is done by "machines" like enzymes,
or by other chemical means isn't the main issue. I'm conf ident that
technologies that emerge from nano will use both.
Dan Colbert
From Dustin Carr:
Brad,
If nanomachines could ever do such things as this, I
assure you they would be much too slow to do anything as significant
as terraforming. Anyway, if you had that many nanomachines, they would
probably be as much of a nuisance as ants.
I sincerely doubt that nanomachines will ever do much
molecular fusion and fission, and certainly they will never do any
nuclear fusion and fission.
Using chemistry can do much of what you are saying, and
can do it quite rapidly. There is no need for nanomachines in this
area.
Dustin
Hi, my name is Daniel and I'm a high school student in
Diamond Bar, Ca. I'm very interested in this stuff. I was wondering,
if biology is nanotechnology that works, can't you just work with
organic materials and other natural chemicals on the nano lev el
instead of metallic materials and other human-made substances? Are
natural or organic substances any different from the man-made except
the fact that they are not that techy in our human mentality? Or is
this all just a crazy thought?
Thank you, From Dustin Carr:
Daniel,
Many researchers are looking at organic materials for
both nanoelectronic and micro/nanomechanics. I myself am embarking on
a project to make nanomechanical systems using polymers. Researchers
elsewhere, such as George Whitesides at Harvard and James To ur at
Univ. of South Carolina, are looking at systems of self-assembling
organic molecules to be used for electronics and nanofabrication.
Harold Craighead's group at Cornell has been looking into
self-assembled monolayers of organic molecules to be used for
lithographic patterning with electron beam tools.
Researchers in nanotechnology are willing to try
anything in order to get things to work on this scale. There is not
really any bias towards metal and semiconductors, except that they
both have excellent mechanical and electrical properties. Organic mol
ecules also have many interesting properties that are continually
being explored, and are certain to become more important for
nanofabrication as time goes
on.
Dustin
From Daniel Colbert:
Daniel,
Keep thinking crazy thoughts -- the world needs more
creativity! Actually, it's not so crazy at all. First, as I've said
above, there already are lots of biological nanomachines, e.g.,
enzymes. More to your point, I think, is an area being pursued for a
future generation of electronics, built largely from organic mol
ecules, called "molecular electronics." The idea is to use molecules,
which are intrinsically nanoscale, as the elements and connectors for
electronic circuits and devices. The need is coming: the steady
miniturization of
integrated circuits we've seen over the past 25 years (following the
celebrated Moore's Law), is approaching a brick wall. The technologies
currently used by the semiconductor industry will soon be unable to
produce feature sizes of metal on silicon small enough to continue the
trend. The industry requires new technologies if it desires to
continue.
Another approach that departs from the semiconductor
industry model is molecular electronics. The field is a couple of
decades old, with not a great deal to show for it, but recent (nano)
developments may make it blossom. Our group has great interest in
using carbon nanotubes, a class of which are coherent metallic
conductors (quantum wires), as a
basis for a molecular electronics. This should get fun in the next few
years!
Dan Colbert
Hello,
I am very interested in most aspects of science, and
have a question about nanotechnology: Could you make your nanodevices
have a power source strong enough to broadcast a radio signal out of
the body? If so, what source of power would you use? I was
considering: if you were not putting these nanodevices in the body,
but rather in outer space, could you use a radioactive isotope as a
power source? Also, could you
make a nanodevice that could levitate in the air by covering it in a
reactive surface of fans?
Andrew Cantino From Daniel Colbert:
Andrew,
Most nanodevices, including MEMS (microelectromechanical
systems) that have been discussed or made, do not carry their power
source with them, although this is not prohibited in principle.
Rather, they are somehow connected, mechanically (e.g., an atomic
force microscope tip,
or an electrochemical sensor) or electromag netically (e.g., a
nanoantenna) to the macroscopic world for their power. The
application, design and power requirements will dictate how power can
be delivered to the device.
Dan Colbert
From Dustin Carr:
Andrew,
These are all interesting ideas. We could probably make
short range adio transmitters that could go inside a body. I don't
know about the est. For a levitating device, the problem would be that
power sources are usually pretty heavy, but that is an interesting
question.
Dustin
I just finished reading about the nanotech of the future, and I
enjoyed the possibilities. I would like to ask what you think of my
ideas.
1] A nanotech suit with the capibilty to be programed to
lock onto the D.N.A. of one person and change according to the
conditions. For example, The suit would take on the form of a dress
suit in the morning, and pants and a t-shirt in the afternoon. This
same suit could take on the form of a revolutionary space suit. 2]
Some form of nano-transportation. For example, a car made completely
of nano-machines. Or a space shuttle made the same way.
P DOUBLE L
From Daniel Colbert:
I think it's great to dream about possibilities. I tend
to feel that the kinds of things you are talking about are rather too
far down the road to comment on very seriously. Most scientists and
engineers in nano are working right now towards establishin g some
measure of control over atoms and molecules at a pretty fundamental
level. This is necessarily rather incremental. Science doesn't
typically work too well when very big bites are attempted at once.
Dan Colbert
From Dustin Carr:
P Double L,
Cool ideas, but you would do better to go into science
fiction writing than nanofabrication.
I don't want to disappoint everybody, but most people
who consider themselves nanotechnologists do not do research into
anything resembling these ideas, nor do they believe that such things
will ever really exist. That does not mean that they won't, it is just
that many unforeseeable events must occur before we can even come
close to achieving this.
Some might say that it takes vision to bring great
things into reality. I agree fully. For instance, it took vision for
engineers to recognize the importance of the transistor, and extend
into the modern computer. It took vision for electrical lines to be
strung across the world after electricity was understood.
I question, however, the usefulness of a vision that is
not based on anything that is currently achievable with any of the
existing technology. Not a single micromachine has ever been used to
assemble anything significant atom by atom, or molecule by mole cule.
We all see pictures of designs made of single atoms placed on a
surface, what we are not told is that those atoms will move around,
and the patterns will fade away within a few hours after they are
made.
So the vision of nanomachines running our world and
having extensive usefulness is built upon techonologies that do not
even exist at this time. It is like having a vision of building the
Hoover Dam before electricity was discovered and understood.
Nanomachines will have an important niche in our
technology in the future, but it is doubtful that they will ever play
a major part in our daily lives. Sorry to disappoint those of you who
may have been led to think otherwise, but at least it makes for g ood
science fiction. I think the advancements that are being made in
electronics, biophysics, communication, etc., due to nanofabrication
will still be enough to make the technology of the future something
worth dreaming about.
Dustin
I think it's facinating that in such a short discussion,
the reprocussions of nanotechnology have ranged from the development
of the ultimate utopian society to the ultimate destruction of
mankind. Relax guys. They said the same things about robots.
Michael
From Dustin Carr:
Heck, they said the same thing about light bulbs. From Daniel Colbert:
Michael, Hear, hear.
Hi! I have always wondered how you can construct such a
tiny thing like a nanoguitar and make it actually work. It is pretty
neat if you ask me! Do you use robots to make them? I've looked around
and found out that you use powerful microscopes to look at them. Is
this a fun job for you? Drew,
Almost all scientists love their work. I made the
nanoguitar using a technique called electron-beam lithography. I use a
large machine that generates a super-small beam of electrons and
shoots these electrons at the surface of a silicon wafer that is coa
ted with a thin layer of a plastic material. The electrons actually
break chemical bonds in this plastic material, allowing me to remove
the exposed areas with solvents such as alcohol.
Once this is done, the rest is pretty easy. I use
various tools and chemicals that allow me to carve away the silicon
material, leaving me with the design of the guitar.
I don't actually play this nanoguitar. It is just a
demonstration of the type of technology we are developing. For my
research, I make mechanical devices of a similar size to the
nanoguitar. I use these to explore the mechanical behavior of
ultrasmall sil icon structures, research that is important so that we
can make smaller and smaller mechanical devices.
Dustin
I am fascinated by nanotechnology from the point of view
of an ordinary person. Having read Neal Stephenson's novel and various
articles about the possibilities, one thing stands out: If you can
develop nanotechnology that works, unless it is very expe nsive, it
will render a huge number of construction and manufacturing processes
obsolete and redundant. Little factories that can endlessly replicate
(given raw material and energy) could tackle any construction project,
small or large. While this confers many benefits, will it not have a
huge impact on society as it is now? I can remember back in the 70s
when people talked of the "leisure society." This might actually bring
it to reality, except society does not have structures in place to
make such a tr ansition smoothly. Do you have thoughts about these
matters? I think history has made it abundantly clear that we cannot
ignore new technologies, we must embrace them. That does pose a large
question for me -- if I can't program computers, what do I do for a
living in the 21st century?
I would be really pleased to hear any thoughts from you
or your colleagues about what the impact might be.
Yours, From Dustin Carr:
Mr. Bolton,
We are still a long way from many of the advancements
you mention. Nonetheless, your point is valid. Scientific progress has
led to remarkable changes in the way we all have lived over the past
hundred years, and it is reasonable to expect that this will continue.
A technical education is always an advantage, but the world will
always need many types of artisans and laborers, no matter how
advanced science and nanotechnology becomes.
Don't worry about the future. Whatever changes occur
will happen gradually enough for us all to keep up with them.
Programming computers is a valuable skill, but just being able to use
computers and software is most important.
Dustin
From Daniel Colbert:
Dear Jocelyn,
I think you are exactly right when you say that "we must
embrace [new technologies]." Advances are going to happen since human
beings are built to be inquisitive. At the same time, I believe we
should always strive for awareness of the societal impact of
technological advances. We do have choices over what directions we
pursue, and over how we use technologies. For example, we might decide
that more money should be spent on solar energy technology so that we
don't pollute the planet by burning fossil fue ls. Simultaneously, we
might place limitations on the amount of pollution we are producing as
we continue burning fossil fuels. We should never feel that technology
is in control of us, as I believe we tend to do as a society. Part of
being a society is d eciding together how we should behave as a group.
Now, to get back to the nano side of your question: I
wouldn't worry too much about nanotechnology displacing jobs. All
emerging technologies have fostered such fears, usually without solid
reason. Typically, there arise at least as many new opportunitie s
from new technologies as are "lost." Consider one of the most
important technological developments in history: the printing press.
Quite a few monks were thrown out of their work of copying
manuscripts, but think
of what was enabled: printers, paper man ufacturers, book binders,
sellers and distributors, journalists, readers(!), not to mention
papparazzi (ok, bad example). The result of most new technologies has
been MORE opportunities, not less.
Finally, as I will no doubt return to in other messages,
I have serious doubts about the so-called "Universal Assembler." I
don't think the world is likely to be transformed by nanoscale
machines that replicate themselves and do any task we program them to
do. I think what is much more likely is the development of highly
specialized nanoscale devices, machines and materials that behave in
ways we design, much as nature has, over billions of years of
evolution designed her nanoscale machines -- enzymes - - to perform
highly specific chemical reactions.
Dan Colbert
Hi, I find your work very fascinating. I was wondering
what projects each of you are currently working on and what
implications those projects might have on my and my children's
futures. From Dustin Carr:
Monty,
I work on a variety of projects that explore practical
ways to make nanoscale structures for electronics and
micro/nano-mechanics. It is hard to envision the exact impact that
work like this will have on the future. The most obvious impact is
that it will pave the way for many more generations of faster and
faster computers. Micromechanics will also allow us to create many
tiny machines that have special uses (such a accelerometers in
airbags). The implications can not even be
guessed at. We are only lay ing the groundwork now for nanotechnology.
Dustin
From Daniel Colbert:
Dear Monty,
Thanks for your question. I work closely with Rick
Smalley at Rice University, where fullerenes (e.g., buckyballs) were
first discovered. We now work on the cousins of buckyballs --
fullerene nanotubes -- pure carbon entities consisting of a planar
sheet of graphite (graphene) rolled up into a cylinder. It may have
either a single layer (typically 1-2 nanometers in diameter) or 5-30
concentric layers. We are working almost exclusively with the former,
single-wall nanotubes (SWNTs), because they are intrinsically freer of
defects than their multiwall brothers. This means that all their
material properties, such as strength, stiffness, toughness,
electrical and thermal conductivites, can be quite close to the ideal.
This is not the case for any other material, where defects always
limit (often by factors of 100 or more) material properties. For
example, when you pull on a steel wire, it never breaks in pracatice
when all the atoms on either side of a plane in the material suddenly
break their bonds simulteaneously. Instead, a crack develops due to
stresses built up at a defect, and runaway propagation ensues,
breaking the wire at dramatically lower tensile forces than would be
predicted if defects are ignored. SWNTs, with their very high degree
of perfection (i.e., nearly every carbon atom is in just the "right"
place), offer the
possibility for material properties very close to the idea, which
happen to be wonderfully high. For example , SWNTs are already known
to be the stiffest fibers known, and almost certainly the strongest.
Their electrical properties are also of immense interest: they
constitute quantum wires, exhibiting coherent transport of electrons
over relatively long distanc es. They may provide a unique basis for
molecular electronics, a hoped-for new generation of electronic
devices. The list of potential applications can go on, but I'll
reserve further discussion for other questions.
Our research has two main prongs. The first is to
develop what we call the "molecular science and technology of
fullerene nanotubes." This comprises activities such as taking raw
SWNT material consisting of tangles of long SWNTs, and purifying it,
cutting it into short lengths that can be manipulated, separating them
from one another, sorting them by length and type, derivatizing their
ends and sides, and assembling them into useful arrangements. These
activities together form the enabling technologies f or making useful
materials and devices from these incredible objects.
None of these applications will mean much, however, if
we are forever stuck with the tiny amounts now available. The field
has undergone an explosion over the past two years largely as a result
of the discovery in our lab at Rice of a new method to produc e much
higher quality SWNT material than had previously been available,
allowing many of the
fundamental studies characterizing the intrinsic properties of these
tubes. Nevertheless, this method only makes around 10 grams of
material per day, and is not easy to scale to larger amounts. We feel
that ultimately, ton amounts of this material will be needed, and a
scaleable, much more economical method for production will be
required. Our group is fast at work on exploring routes to bulk
production of SWNTs .
Dan Colbert
I do not believe that the scientists who are working on
"building the future one molecule at a time" truly understand the
future they are building. Consider this: If I get ahold of a nanorobot
that can build anything from basic compounds, I could buil d anything
I wanted. Nerve gas, weapons, robot drones, soldiers, whole cities
underground, a tower that reached into space to launch space craft,
anything. Man's heart is set on evil, it is in our nature and this
will be the undoing
of us all. You're buil ding your own executioner one molecule at a
time.
From Dustin Carr:
The same has been said many times about many
technologies, yet mankind is still doing pretty well. Scientists are
usually too busy thinking about solutions to ponder problems such as
these.
From Daniel Colbert:
Dear Travis,
Please see my response to Jocelyn. I can't agree with
you about "Man's heart [being] set on evil." We are not all going back
to being hunter-gatherers; new technologies will continue, and we need
to accept that. We can, however, always be vigilant about how we use
technology. This is something I think we can all agree on, and work
together on.
Dan Colbert
I'm wondering what you all think of Eric Drexler and
his, I guess you'd call it, "utopian" vision. From Dustin Carr:
Paula,
It is important to have visions, even if the visions
don't turn out to resemble reality. Drexler's vision is a very, very
long way from becoming a reality, and it is not the primary focus of
nanotechnology today. But who knows? With a couple of groundbrea king
discoveries, we could be well on our way to his vision by the end of
the next century.
Dustin
From Daniel Colbert:
Dear Paula,
As I hinted to Jocelyn, I am not a Drexlarian. I do feel
that Eric Drexler has done wonders publicizing the possibilities for
nanotechnology, and most people in the field are grateful for that and
admire what he has done. The difficulty that some of us have is with
his specific vision, particularly the "universal assembler." Rather
than my going on at length, I'd like to refer you to remarks made by
Rick Smalley at the 1996 Welch Foundation meeting, in which he
outlines his argument against the Drexlarian universal assembler. You
can find this online at http://cnst.rice.edu/NanoWelch.html.
Dan Colbert
I have seen some of the videos of micromachines and a
lot of them have small bugs like aphids, dust mites and spider mites
on them. Do these little things cause problems in the
micromachines? Dear Drew,
The pictures you have seen with mites on MEMS devices
are to give a feel for scale. As far as I know, they are not known to
interfere with the operation of the devices (I think they know to keep
away!). However, dust is a problem when manufacturing MEMS, and
integrated circuits, for that matter. That's why it's all done in
"clean rooms," where dust content is kept to a VERY low level, and
why, as in the Intel commercials, workers must where special suits.
Dan Colbert
We've received many questions from people concerned
about the social implications of a futuristic vision like Eric
Drexler's where nano factories can build compounds and structures from
their base molecular parts. Dennis Costello from the Cornell
Nanofabrication Facility responds to this notion below.
The question is what will people do for a living in the
absence of a production-oriented economy? Or, more precisely, in an
economy which includes completely automated production? That's a very
interesting question, and one which apparently has been addre ssed
only in the realm of science fiction. People have looked at pieces of
it -- the Luddites are a famous example of people feeling their
livelihoods threatened by automated production, and reacting in a very
human, although negative way -- they smashed the machines. One can
find a
similar message in a classic movie from the late 40s (early 50s?)
whose title was something like 'The Man in the Grey Wool Suit' --
where an indestructible fabric was invented, putting mill workers'
jobs at risk. For now, though, the problem also lies in the province
of science fiction. Eric Drexler's predictions aside, the foreseeable
future does not include universal assemblers; machines that pick atoms
from a soup of raw materials and, as instructed, build the car or
building or suit
of clothes. The foreseeable future does include nanomachines that are
very like today's computer chips, but with moving parts. This
technology will allow people to build things like accelerometers for
car air bags that are more rel iable, cheaper and less expensive than
other designs. Prosthetics for those who are deaf due to injury or
disease to the cochlea. Hand-held inertial navigation systems cheap
enough to take on a camping trip. TVs that fill an entire wall, but
are less than an inch thick, and with each pixel implemented as a
triad of flappers moving 60 times a second. Optical-fiber switching
systems where the fiber itself is moved from one place to another.
Neat gadgets. Useful gadgets. But in the great scheme of things, ga
dgets that represent incremental changes to the economy, not
revolutionary changes.
History is indeed replete with the struggle between
those who would put technology to use for evil purposes, and those
with more noble aims. Technology is simply and literally knowing how
to do things. The choice of what things to do is another subject en
tirely -- philosophy. People have, for many years, predicted that
particular technologies would spell the doom of the entire human race,
if not more. The machine gun, the torpedo and submarine, the
dreadnought (battleship), the tank, the atom bomb. And th ose who have
foretold doom have not been entirely wrong. But I'm optimistic enough
to believe that the good guys always win in the end. Given that
nanotechnology represents an evolution and not a revolution in the
abilities of humanity, I'm not too worrie d that the Saddam Husseins
of the world are going to use it.
by Noah Robischon
http://www.discovery.com/stories/technology/nanotech/nanotech.html
Bob
from Lincoln University
Jefferson City, MO
-Daniel
The Science Page
Dustin
Dan Colbert
-- Drew
Jocelyn Bolton (Mr)
Monty
- Paula
-Drew