Nanotechnology's descent into matter's minuteness
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 hisnanotruck, which couldmove 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."
(c) Copyright 2000. The Christian Science Publishing Society