Nanotechnology's Descent into
Matter's Minuteness Source: Christian Science Monitor April 13, 2000
ST. LOUIS
The long rectangular device that powers an experiment in
Rod Ruoff's lab could fit in a pack of chewing gum and looks equally
unspectacular.
You can't see it move. The springs on either side of its
tiny motor push nothing heavier than carbon tubes so small they're
measured in millionths of a millimeter. Nevertheless, scientists here
at Washington University and around the country believe such
experiments in nanotechnology could one day change the world.
By building machines and materials with atomic
precision, researchers believe they'll create faster computers,
lighter spacecraft, and airplane wings so efficient they'll adjust to
airflow like a flexible skin. Medical robots would snatch a page from
science-fiction's "Fantastic Voyage" and travel through the body
fixing things. Computer components the size of a molecule could put a
supercomputer into the palm of your hand.
But the same technology that holds out such promises
also conceals inherent dangers. Wing sensors could easily become
invisible listening devices. Tiny robots that manipulate atoms could
carry designer viruses into the battlefield or a public building.
Such fears remain speculative. But the science of
nanotechnology is moving so fast that such scenarios could become far
too real in a few decades. So what should a society do? Plow ahead in
search of the good? Or slow down for fear of the bad? That ethical
debate is just now bubbling to the surface as academia, the federal
government, and business begin a full-scale assault on the smallest
frontiers of science.
"With the control of matter that we are talking about,
there will be unimaginable inventions," says Dr. Ruoff, who heads the
Laboratory for the Study of Novel Carbon Materials. If the optimists
are right, anything people can design on a computer they will be able
to make out of matter.
What is nanotechnology?
Nanotechnology involves such a steep descent into the
minuteness of matter that it was considered science fiction until a
few years ago. Nanometers are 100 times smaller than the fine lines
computer companies currently etch on silicon chips, 5,000 times
smaller than a human hair. At that level, scientists are manipulating
clumps of atoms and sometimes individual atoms.
It's this incredibly small scale that fuels the hope -
and hype - surrounding nanotechnology. Theoretically, engineers will
one day be able to rearrange materials at the atomic level to create
almost anything they want within the constraints of chemistry. A car
body that's as hard as diamonds and lighter than steel? No problem,
according to the visionaries. A space vehicle that's cheap to launch?
Make way for handsized satellites with several components shrunk to
nanoscopic scale.
And no need to take up scientists' valuable time
assembling all those atoms. Just make tiny robots - nanobots - to make
other nanobots. Once you've assembled 1 million of them, turn them
loose to build whatever you can dream up.
It's these self-replicating nanobots that fuel most of
the futuristic fears. What if they got loose? Or a terrorist set them
free in a large city? All the fears now bound up with the spread of
biological weapons ride on the back of future nanotechnology robots.
Bill Joy, cofounder and chief scientist of Sun
Microsystems, in this month's edition of Wired magazine warns: "I
think it is no exaggeration to say we are on the cusp of the further
perfection of extreme evil, an evil whose possibility spreads well
beyond that which weapons of mass destruction bequeathed to the
nation-states, on to a surprising and terrible empowerment of extreme
individuals."
It's not just nanotechnology that scares the
well-respected Mr. Joy. It's the combination of genetic engineering
and robotics brought to the nanoscale that feeds his apprehension that
human beings could build machines that replace them. His article is
entitled: "Why the Future Doesn't Need Us."
Many nanotechnology researchers argue that such dark
thoughts are unfounded - or at least extremely premature. "A lot of
this, I think, is hysteria," says Shuvo Roy, a biomedical engineer
working on medical pills with nanosensors at the Cleveland Clinic
Foundation. "People will find more benefits of this technology than
the downside."
"I don't see the frenzy of the danger of a nanosystem,"
adds James Tour, a chemistry professor at Rice University in Houston
who is using the technology to build cheap computer chips and a
molecule-mover called a "nanotruck." "We could blanket Baghdad with
nanotrucks, but so what? ... I can't even think about how you can
build a nanosystem with a mind of its own. In 100 years, maybe!"
For the moment, researchers are preoccupied with
figuring out the basic science surrounding nanotechnology. Here at
Washington University, for example, Ruoff and his team are
investigating the properties of nanotubes - hollow tubes of carbon
atoms. In a basement lab, researchers Oleg Lourie and Richard Piner
use the group's tiny spring machine to break them apart, push them
together again, and measure the forces.
It turns out that nanotubes are handsomely endowed with
several important traits. It takes roughly 50 to 100 times more force
to pull them apart than a strand of steel of equal weight. They
conduct electricity. And by crimping them temporarily, researcher
Kevin Ausman is working on ways to create an electronic gate that
could turn them into molecular switches that could be used in future
computers.
Big hurdles remain. Nanotubes tend to bunch up in
solution so it's hard to get a single tube where you want it. Another
problem: Nanotubes don't amplify the signal the way traditional
silicon chips do.
They're just cheaper
That's why Dr. Tour at Rice University is working on a
hybrid chip that incorporates silicon and his newfangled
nanomolecules. The initial chips - expected in three to five years -
won't be much faster or smaller than today's versions. But they'll be
far cheaper to produce because they won't require the clean-room
extremes of today's billion-dollar semiconductor factories. And they
could breathe new life into the chip industry. Using conventional
methods to shrink the size of semiconductors, chipmakers could run
into physical limitations
of matter in less than a decade. Hybrid chips would delay such
problems. Eventually, nanotechnology researchers may deliver much
tinier chips with molecular-sized transistors. When that happens, Tour
adds, a single drop of water will hold more potential transistors than
all thosemade in the last 40 years.
Tour is also nearing completion of his nanotruck, which
could move individual molecules around. "We have the chassis, which
has fully rotating axles," he says. "We have the loading bay. We have
the wheels. We just have to get them on.... Six months from now, we'll
have our driver's license."
A few nanomaterials have hit the marketplace already
(although not everyone considers them true nanotechnology). For
example, Nanophase Technologies Corporation in Burr Ridge, Ill., has
created nanosized zinc oxide, used in sunscreen. By using particles
smaller than the wavelength of visible light, companies can make their
lotions clear instead of opaquely white and still block out the sun.
The company is also working on other nanosized coatings that would
keep wood finish
from fading and make plastic lenses for glasses more
scratch-resistant. By the end of next year, the 11-year-old company
hopes to break even financially.
The science of tininess got a big boost in January when
President Clinton announced the National Nanotechnology Initiative.
Under the plan, the National Science Foundation, along with partners
such as NASA, the National Institutes of Health, and the Defense
Department, would dole out money to researchers to further basic
knowledge about how these invisible systems work. Clinton's 2001
budget request includes $495 million for such research.
"We think this will be one of the three major thrusts in
science in the next 10 and 20 years," says Mihail Roco, who heads an
interagency working group on nanoscience within the White House's
National Science and Technology Council. Unlike the other two key
fields, bio-engineering and computers, "this is the first time since
World War II we don't have a commanding lead in an emerging
technology," he says.
Researcher's on a wild ride.
Although some critics say the initiative should be more
tightly focused, many researchers agree that the initiative
legitimizes the science and will accelerate new breakthroughs.
"It's going to be a wild ride," says Ruoff, sitting in
his cluttered Washington University office. While largely optimistic
about what he sees as a plethora of benefits, he worries about the
misuse of the technology for spying on people. In the future, a
nanoscopic device "could be monitoring this whole room and I wouldn't
be able to see it - or possibly detect its presence."
Such invasive devices are already coming to the fore in
slightly larger form, he points out. For example, the Defense Advanced
Research Projects Agency is funding a program called "Smart Dust."
Researchers at the University of California at Berkeley are working to
build communicating sensors smaller than the tip of a ballpoint pen.
By sprinkling millions of them along a strip of land, the military
could monitor enemy troop movements or the approach of guerrillas.
Such micro-electro-mechanical systems (MEMS) could also be used to
allow a computer to translate sign language or mimic a keyboard out of
thin air.
"All that surveillance stuff is coming from MEMS," says
Christine Peterson, president of the Foresight Institute, a nonprofit
think tank in Palo Alto, Calif. "The videocams you can make with MEMs
are so cheap and so small ... we'll have all those [privacy] issues
resolved before nanotech shows up."
The bigger threats posed by the technology fall into two
categories, she says: accidents and intended destruction. Scientists
who take a minimum of precautions will be able to avoid nightmare
accidents, such as releases of nano-organisms into the wild. Intended
destruction, on the other hand, poses real dangers.
"You can make weapons out of molecular machinery that
can be pretty scary," Ms. Peterson says. And, unlike the manufacture
of nuclear devices, nanotech weapons don't require big, expensive
facilities to produce. "There's a real concern that this is going to
be easier for rogue nations to develop and hide," she adds, which is
very similar to biological weapons today.
That's why critics argue nanotechnology as well as
genetic research should be slowed. "Given the incredible power of
these new technologies, shouldn't we be asking how we can best coexist
with them?" Joy writes.
But nanotechnologists counter it's not realistic to
hamper potentially beneficial research because of futuristic fears.
"This is not something that can be stopped," says Peterson. "Let's
look at the safety issues, let's look at the arms-control issues, and
let's try to heavily fund the good guys."
"This is not any looming apocalypse or paradise," adds
David Padowitz, a nanotech researcher at Amherst College in Amherst,
Mass. "We have to build the silly things first."
by Laurent Belsie
(belsiel@csps.com)
Staff Writer
http://www.csmonitor.com/durable/2000/04/13/fp20s1-csm.shtml