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