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