Published: June 2006

Nano’s Big Future

Marble Blue

Welcome to the World of Nanotechnology

Tiny technology promises big rewards. Some may already be in your closet.

By Jennifer Kahn
Photograph by Mark Thiessen
National Geographic Photographer

“I sit before you today with very little hair on my head. It fell out a few weeks ago as a result of the chemotherapy I’ve been undergoing. Twenty years ago, without even this crude chemotherapy, I would already be dead. But 20 years from now, nanoscale missiles will target cancer cells in the human body and leave everything else blissfully alone. I may not live to see it. But I am confident it will happen.” Richard Smalley spoke these words on June 22, 1999. He died of non-Hodgkin’s lymphoma on October 28, 2005. The 62-year-old Nobel Prize-winning chemist was a nanotech pioneer.

A tsunami is unnoticeable in the open ocean—a long, low wave whose power becomes clear only when it reaches shore and breaks. Technological revolutions travel with the same stealth. Spotting the wave while it’s still crossing the ocean is tricky, which explains why so few of us are aware of the one that's approaching. Nanotechnology has been around for two decades, but the first wave of applications is only now beginning to break. As it does, it will make the computer revolution look like small change. It will affect everything from the batteries we use to the pants we wear to the way we treat cancer.

The main thing to know about nanotechnology is that it’s small. Really small. Nano, a prefix that means “dwarf” in Greek, is shorthand for nanometer, one-billionth of a meter: a distance so minute that comparing it to anything in the regular world is a bit of a joke. This comma, for instance, spans about half a million nanometers. To put it another way, a nanometer is the amount a man’s beard grows in the time it takes him to lift a razor to his face.

Nanotechnology matters because familiar materials begin to develop odd properties when they’re nanosize. Tear a piece of aluminum foil into tiny strips, and it will still behave like aluminum—even after the strips have become so small that you need a microscope to see them. But keep chopping them smaller, and at some point—20 to 30 nanometers, in this case—the pieces can explode. Not all nanosize materials change properties so usefully (there’s talk of adding nano aluminum to rocket fuel), but the fact that some do is a boon. With them, scientists can engineer a cornucopia of exotic new materials, such as plastic that conducts electricity and coatings that prevent iron from rusting. It’s like you shrink a cat and keep shrinking it, and then at some point, all at once, it turns into a dog.

Substances behave magically at the nanoscale because that’s where the essential properties of matter are determined. Arrange calcium carbonate molecules in a sawtooth pattern, for instance, and you get fragile, crumbly chalk. Stack the same molecules like bricks, and they help form the layers of the tough, iridescent shell of an abalone.

It’s a tantalizing idea: creating a material with ideal properties by customizing its atomic structure. Scientists have already developed rarefied tools, such as the scanning tunneling microscope, capable of viewing and moving individual atoms via an exquisitely honed tip just one atom wide.

“Nano’s going to be like the invention of plastic,” says Paul Alivisatos, associate director of physical sciences at Lawrence Berkeley National Laboratory’s new nanofabrication center. “It’ll be everywhere: in the scalpels doctors use for surgery and in the fabrics we wear.” Alivisatos already owns a pair of stain-resistant nanopants from the Gap, made from fibers treated with fluorinated nanopolymer. “I spilled coffee on them this morning, and it rolled right off.”

On a table in a lab at Rice University, André Gobin, a graduate student, is working with two slices of raw chicken. He nudges the slices together so they touch and dribbles greenish liquid along the seam. The liquid is a solution of nanoshells: minuscule silica beads covered, in this case, with gold. Switching on an infrared laser, Gobin deftly traces the beam down the length of the green line. Tweezing the chicken up, he dangles what is now a single piece of meat.

Someday soon surgeons may be able to use a nanoshell treatment like this to reconnect veins that have been cut during surgery. “One of the hardest things a doctor has to do during a kidney or heart transplant is reattach cut arteries,” says Gobin. “They have to sew the ends together with tiny stitches. Leaks are a big problem.” With Gobin’s nanoshell solution a surgeon could simply meld the two ends and get a perfect seal. It would make grafting veins as easy as soldering wire.

Although much of nanotechnology’s promise remains unrealized, investment in the field is booming. The U.S. government allocated more than a billion dollars to nanotechnology research in 2005—more than twice what it spent on sequencing the human genome when that project was at its height. Japan and the European Union have spent similar amounts, and even smaller countries are hurrying to get a foot in the door. A Korean company has used nanosilver-based antibacterials in refrigerator interiors. The same material can be incorporated in bandages. The hope is the same on all fronts: to get the jump on a growing global market that the National Science Foundation estimates will be worth a trillion dollars by 2015.

One reason for the rapid global spread of nanotechnology is that the entry cost is comparatively low. Countries that missed out on the computer revolution because they lacked the capital to build vast, high-tech factories that make silicon chips are less likely to miss the nanotech wave.

“It’s science you can do in a beaker,” says Stephen Empedocles, vice president of Nanosys, a company that’s developing cheap solar nanostructures. Traditionally, the manufacture of solar-energy cells has required a multimillion-dollar fabrication facility that cooks sheets of glass at extremely high temperatures until the atoms order themselves into a receptive latticework. Solar nanostructures, on the other hand, grow like rock candy. You can “mix them up in a beaker with a hundred dollars’ worth of starter chemicals,” Empedocles says, and then paint them on window glass to turn an entire building into a solar-energy generator. Or, they might be embedded in the plastic body of a cell phone or laptop computer.

For a hundred dollars, in fact, anyone can buy nanoparticles—specifically a gram of carbon nanotubes—online. Place the order, and you’ll receive a small ziplock bag of what looks like soot tucked inside a cardboard FedEx envelope along with some safety instructions. (They recommend gloves to keep the carbon slivers off the skin and a respirator to keep the tiny black specks from entering the lungs.)

There’s not much you can do at home with a thimbleful of carbon nanotubes. But some of their mysteries are revealed in another Rice University lab, where Matteo Pasquali holds up a test tube containing a few dark threads so stiff that they seem to have been starched and ironed. These are fibers spun from carbon nanotubes—several billion of them—which, in theory, should be stronger than Kevlar, the material in bulletproof vests.

For now, however, the threads are only about as tough as the acrylic found in an ordinary sweater. The reason the threads are weak, Pasquali believes, is because some portion of the billion nanotubes bundled together have hidden breaks. A photo taken through a microscope shows fibers that look like pale gray hairs, some perfectly straight, others frayed and curling. “We have split ends,” Pasquali says with a sigh. “We need a nanotube conditioner.”

Carbon has proved a useful element in nanotechnology. One of the science’s building blocks is a molecule that contains 60 carbon atoms arranged in a sphere. A molecule of C6o looks like the geodesic dome invented by Buckminster Fuller, thus its nickname: buckyball.

Richard Smalley and colleagues discovered the buckyball in 1985, and in 1996 Smalley and two others earned a Nobel Prize in chemistry for the deed. Until his recent death, Smalley was a bucky fanatic. He renovated his house, close to the Rice University campus in Houston, with a glass skylight shaped like half a buckyball, with precisely proportioned steel struts representing the bonds between atoms.

Smalley was openly proselytical about the merits of buckyballs and a particular fan of their relatives, carbon nanotubes. (“Fifty to a hundred times stronger than steel and one-sixth the weight!” he often pronounced as though reporting the achievements of a precocious child.)

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