NANOTECHNOLOGY

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In 2000, a group of scientists from the University of Michigan’s Center for Biologic Nanotechnology traveled to the U.S. Army’s Dugway Proving Ground in Utah. The purpose of their visit: to demonstrate the power of “nano-bombs.” These munitions don’t exactly go “Kaboom!” They’re molecular-size droplets, roughly 1/5000 the head of a pin, designed to blow up various microscopic enemies of mankind, including the spores containing the deadly biological warfare agent anthrax.

The military’s interest in nano-bombs is obvious. In the test, the devices achieved a remarkable 100% success rate, proving their unrivaled effectiveness as a potential defense against anthrax attacks. Yet their civilian applications are also staggering. For example, just by adjusting the bombs’ ratio of soybean oil, solvents, detergents, and water, researchers can program them to kill the bugs that cause influenza and herpes. Indeed, the Michigan team is now making new, smarter nano-bombs so selective that they can attack E. coli, salmonella, or listeria before they can reach the intestine.

If you’re a fan of science fiction, you’ve no doubt encountered the term nanotechnology. Over the past 20 years, scores of novels and movies have explored the implications of mankind’s learning to build devices the size of molecules. In a 1999 episode of The X-Files titled “S. R. 819,” nanotechnology even entered the banal world of Washington trade politics, with various nefarious forces conspiring to pass a Senate resolution that would permit the export of lethal “nanites” to rogue nations.

Yet since 1999, a series of breakthroughs have transformed nanotech from sci-fi fantasy into a real-world, applied science, and, in the process, inspired huge investments by business, academia, and government. In industries as diverse as health care, computers, chemicals, and aerospace, nanotech is overhauling production techniques, resulting in new and improved products—some of which may already be in your home or workplace.

Silicon Fingers

Meanwhile, nearly every week, corporate and academic labs report advances in nanotech with broad commercial and medical implications. In 2000, for example, IBM announced it had figured out a way to use DNA to power a primitive robot with working silicon fingers 1/50 as thick as human hair. Within a decade or so, such devices may be able to track down and destroy cancer cells. Over at Cornell University, researchers have developed a molecular-size motor, built out of a combination of organic and inorganic components, that some dub nanotech’s “Model T.” In tests announced in 2000, the machine’s rotor spun for 40 minutes at 3 to 4 revolutions per second. When further developed, such motors will be able to pump fluids, open and close valves, and power a wide range of nanoscale devices.

These inventions and products are just the beginning of what many observers predict will be a new industrial revolution fostered by man’s growing prowess at manipulating matter one atom, or molecule, at a time. Because of nanotech, all of us will see more change in our civilization in the next 30 years than we did during all of the 20^th century.

Note 

Nanotech takes its name from the nanometer, a unit of measurement just one billionth of a meter long.

Imagine the possibilities. Materials with 10 times the strength of steel and only a small fraction of the weight. Shrinking all the information housed at the Library of Congress into a device the size of a sugar cube. Or detecting cancerous tumors when they are only a few cells in size.

To build such objects, engineers are employing a wide range of techniques, borrowed from bioengineering, chemistry, and molecular engineering. Such feats include imitating the workings of the body, where DNA not only programs cells to replicate themselves but also instructs them how to assemble individual molecules into new materials such as hair or milk. In other words, many nanotech structures build themselves.

Atom by Atom

The inspiration for nanotech goes back to a 1959 speech by the late physicist Richard Feynman, titled “There’s Plenty of Room at the Bottom.” Feynman, then a professor at the California Institute of Technology, proposed a novel concept to his colleagues. Starting in the Stone Age, all human technology, from sharpening arrowheads to etching silicon chips, has involved whittling or fusing billions of atoms at a time into useful forms. But what if we were to take another approach, Feynman asked, by starting with individual molecules or even atoms, and assembling them one by one to meet our needs? The principles of physics, as far as Feynman could see, did not speak against the possibility of maneuvering things atom by atom.

Four decades later, Chad Mirkin, a chemistry professor at Northwestern University’s $45 million nanotech center, used a nanoscale device to etch most of Feynman’s speech onto a surface the size of about 10 tobacco smoke particles—a feat that Feynman would no doubt have taken as vindication. But the course science took to achieve such levels of finesse has not always been straightforward. Nor has it been lacking in controversy.

Indeed, some scientists are alarmed by nanotechnology’s rapid progress. In 2000, the chief scientist at Sun Microsystems, created a stir when he published an essay in Wired magazine warning that in the wrong hands, nanotech could be more destructive than nuclear weapons. Influenced by the work of Eric Drexler, an early and controversial nanotechnology theoretician, the scientist predicted that trillions of self-replicating nanorobots could one day spin out of control, literally reducing the earth’s entire biomass to “gray goo.”

Most researchers in the field don’t share that type of concern. They are compelled to keep going. Researchers are knocking on the door of creating new living things, new hybrids of robotics and biology. Some may be pretty scary, but they have to keep going.

The early payoffs have already arrived. Computer makers, for example, use nanotechnology to build “read heads,” a key component in the $45-billion-a-year hard disk drive market, which vastly improve the speed at which computers can scan data. Another familiar product, Dr. Scholl’s brand antifungal spray, contains nano-scale zinc oxide particles—produced by a company called Nanophase Technologies—that make aerosol cans less likely to clog. Nanoparticles also help make car and floor waxes that are harder and more durable and eyeglasses that are less likely to scratch. As these examples show, one huge advantage of nanotech is its ability to create materials with novel properties not found in nature or obtainable through conventional chemistry.

What accounts for the sudden acceleration of nanotechnology? A key breakthrough came in 1990, when researchers at IBM’s Almaden Research Center succeeded in rearranging individual atoms at will. Using a device known as a scanning probe microscope, the team slowly moved 35 atoms to spell the three-letter IBM logo, thus proving Feynman right. The entire logo measured less than three nanometers.

Soon, scientists were not only manipulating individual atoms but also “spray painting” with them. Using a tool known as a molecular beam epitaxy, scientists have learned to create ultrafine films of specialized crystals, built up one molecular layer at a time. This is the technology used today to build read-head components for computer hard drives.

One quality of such films, which are known as giant magnetoresistant materials, (GMRs), is that their electrical resistance changes drastically in the presence of a magnetic field. Because of this sensitivity, hard disk drives that use GMRs can read very tightly packed data and do so with extreme speed. In a few years, scientists are expected to produce memory chips built out of GMR material that can preserve 100 megabits of data without using electricity. Eventually, such chips may become so powerful that they will simply replace hard drives, thereby vastly increasing the speed at which computers can retrieve data.

Natural Motion

The next stage in the development of nanotechnology borrows a page from nature. Building a supercomputer no bigger than a speck of dust might seem an impossible task, until one realizes that evolution solved such problems more than a billion years ago. Living cells contain all sorts of nanoscale motors made of proteins that perform myriad mechanical and chemical functions, from muscle contraction to photosynthesis. In some instances, such motors may be re-engineered, or imitated, to produce products and processes useful to humans.

Animals such as the abalone, for example, have cellular motors that combine the crumbly substance found in schoolroom chalk with a “mortar” of proteins and carbohydrates to create elaborate, nano-structured shells so strong they can’t be shattered by a hammer. Using a combination of biotechnology and molecular engineering, humans are now on the verge of being able to replicate or adapt such motors to suit their own purposes.

How are these biologically inspired machines constructed? Often, they construct themselves, manifesting a phenomenon of nature known as self-assembly. The macromolecules of such biological machines have exactly the right shape and chemical-binding preferences to ensure that, when they combine, they will snap together in predesigned ways. For example, the two strands that make up DNA’s double helix match each other exactly, which means that if they are separated in a complex chemical mixture, they are still able to find each other easily.

This phenomenon is potentially very useful for fabricating nanoscale products. For instance, in 1999, a team of German scientists attached building materials such as gold spheres to individual strands of DNA and then watched as the strands found each other and bound together the components they carried, creating a wholly new material.

Similarly, the 1996 Nobel Prize in chemistry went to a team of scientists for their work with “nanotubes”—a formation of self-assembling carbon atoms about 1/50,000 the width of a human hair. Scientists expect that when they succeed in weaving nanotubes into larger strands, the resulting material will be 100 times stronger than steel, conduct electricity better than copper, and conduct heat better than diamond. Membranes of such fibers should lead to rechargeable batteries many times stronger, and smaller, than today’s.

In 2000, a team of IBM scientists announced that they had used self-assembly principles to create a new class of magnetic materials that could one day allow computer hard disks and other data-storage systems^[vi] to store more than 100 times more data than today’s products. Specifically, the researchers discovered certain chemical reactions that cause tiny magnetic particles, each uniformly containing only a few thousand atoms, to self-assemble into well-ordered arrays, with each particle separated from its neighbors by the same preset distance.

Other scientists have discovered important new self-assembling entities by accident. In 1996, Samuel Stupp, a professor at Northwestern University, was in his lab trying to develop new forms of polymer when he inadvertently came upon “nanomushrooms.” He saw the potential right away. The molecules he had been experimenting with had spontaneously grouped themselves into supramolecular clusters shaped like mushrooms. Soon afterward, Stupp discovered, again accidentally, that he could easily program these supramolecules to form film that behaves like Scotch tape.

Meanwhile, researchers at UCLA and Hewlett-Packard have laid the groundwork for the world’s first molecular computer. Eventually, the researchers hope to build memory chips smaller than a bacterium. Such an achievement is essential if computing power is to continue doubling every 18 to 24 months, as it has for the past four decades. This is because the more densely packed the transistors on a chip become, the faster it can process, and we are approaching the natural limit to how small transistors can be fabricated out of silicon.

Future Phenomena

Finally, where will it all end? Many futurists have speculated that nanotech will fundamentally change the human condition over the next generation. Swarms of programmable particles, sometimes referred to as “utility fog,” will assemble themselves on command. The result could be a bottle of young wine molecularly engineered to taste as if it had aged for decades, or a faithful biomechanical dog with an on/off switch.

Meanwhile, new, superstrong, lightweight nanomaterials could make space travel cheap and easy and maybe even worth the bother, if, as some scientists predict, nanotech can be used to create an Earth-like atmosphere on Mars. And space colonization could well be necessary if the new science of “nanomedicine” extends life indefinitely, manufacturing new cells, molecule by molecule, whenever old cells wear out. It all seems hard to imagine; yet nanotech has already produced enough small wonders to make such big ideas seem plausible, if not alarming—at least to the high priests of science and the IW military strategists.

^[vi]John R. Vacca, The Essential Guide to Storage Area Networks, Prentice Hall, 2002.

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