BY THE middle of this century, the inventor Ray Kurzweil suggests in his 2005 book The Singularity Is Near , human beings will live in perpetual clouds of nanobots, molecule-size robots that spend each moment altering our micro-environments to our precise preferences. Over the longer term, he imagines that nanotechnology—the manipulation of matter at the molecular level—will let us change our shape and appearance, become immortal and transfer our minds with ease between far-flung planets.

By contrast, the thriller writer Michael Crichton describes nanobots running amok in his 2002 novel Prey . With his signature mix of tech savvy and paranoia, Crichton imagines the tiny automatons forming "nanoswarms," clouds that visually mimic human beings in order to infiltrate and destroy us—sort of microscopic, sentient super-kudzu.

Both our hopes and fears regarding nanotechnology have been extreme from the beginning, if we take as the beginning K. Eric Drexler's 1986 book Engines of Creation . Drexler, an engineer, described nanotech as the ultimate fulfillment of humanity's dynamic, self-transforming tendencies: the ability to create whatever we want, whenever we want it, combined with an imperative to take this godlike new power to the stars and turn the universe into our playground.

Drexler also described the dark twin of this vision: the "gray goo" scenario. Self-replicating nanobots, which proliferate by turning surrounding matter into copies of themselves, would go out of control, turning the entire Earth into themselves—the most homogeneous imaginable version of the apocalypse. In the words of a technophilic but precaution-prone acquaintance of mine, a computer programmer who has his wristwatch set to alert him if a tsunami approaches Manhattan: "The gray goo scenario should at least give one pause."

Such disaster fears are already fueling calls for regulation, even with the technology barely out of the cradle. Nanotech-related products will soon account for $2.6 trillion in sales each year, according to a London School of Business/Rice University study. The current applications are concentrated in products that benefit from highly efficient filtering or surface-application processes, such as microchips, car wax and sunscreen. But down the road, the likely applications include molecule-perfect wound-healing, flawless cleaning processes, quantum computing, far easier bioengineering, much more efficient photon and electrical transfer, and much more. In a June 2007 press release, Consumers Union, publisher of Consumer Reports , noted that nanotechnology "promises to be the most important innovation since electricity and the internal combustion engine." At the same time, it called for more testing and oversight, warning that some nanotech applications "might pose substantial risks to human health and the environment."

Angels vs. Robots

Although Consumers Union concedes that "no confirmed cases of harm to humans from manufactured nanoparticles have been reported," it adds that "there is cause for concern based on several worrisome findings from the limited laboratory and animal research so far." It worries that particles that are nontoxic at normal sizes may become toxic when nanosized; that these nanoparticles, which are already present in cosmetics and food, can more easily "enter the body and its vital organs, including the brain," than normal particles; and that nanomaterials will linger longer in the environment. All of this really comes down to pointing out that some particles are smaller than others. Size is not a reliable indicator of potential harm to human beings, and nature itself is filled with nanoparticles. But the default assumption of danger from the new is palpable.

Anti-nanotech sentiment has not been restricted to Consumers Union's relatively short list of concerns. In France, groups of hundreds of protesters have rallied against even such benign manifestations of the technology as the carbon nanotubules that allow Parkinson's sufferers to stop tremors by directing medicine to their own brains. In England members of a group called THRONG (The Heavenly Righteous Opposed to Nanotech Greed) have disrupted nanotech business conferences dressed as angels. In 2005 naked protesters appeared in front of an Eddie Bauer store in Chicago to condemn one of the more visible uses of nanotech: stain-resistant pants.

These nanopants employ billions of tiny whiskers to create a layer of air above the rest of the fabric, causing liquids to roll off easily. It's not quite what Kurzweil and Crichton had in mind, nor is it "little robots in your pants," as CNN put it. But nanotechnology arguably embraces any item that incorporates engineering at the molecular level, including mundane products like this one.

Just as the nano label can be broadly applied to products for branding and attention-grabbing purposes, so too can critics use the label to condemn barely related developments by linking them to the (still hypothetical) problems of nanopollution and gray goo. But there's a danger in thinking of nanotech only in god-or-goo terms. People at both extremes of the controversy fail to appreciate the humble, incremental, yet encouraging progress that nanotech researchers are making. And focusing on dramatic visions of nanotech heaven or hell may foster restrictions that delay or block innovations that can extend and improve our lives.

Water Runs Uphill

To get a look at some of the real nanotech research, neither divine nor gooey, I went on a junket to one nanotech hot spot, visiting researchers in Glasgow, Dundee and Edinburgh. (Scottish Enterprise, a public-private economic development agency that promotes international awareness of such researchers and other Scottish ventures, paid for the trip.) I also made a quick visit to the Edinburgh grave of Adam Smith, a reminder that the Scots are proudly, even pugnaciously, entrepreneurial and inventive—"punching above our weight," as many people in that nation of only 5 million like to put it before rattling off a list of the famous inventors who have come from Scotland.

One of those famous Scots was the 19th-century physicist James Clerk Maxwell. Today, thanks to nanotech, one of his countrymen may be on the verge of creating a workable version of a system that Maxwell first imagined. "It's a little bit frustrating when people talk about nanobots and gray goo, because it's not as exciting as what we're really going to be able to do," says Edinburgh University chemist David A. Leigh. Leigh believes nanotech might allow us to create a system physicists call Maxwell's Demon. With virtually no expenditure of energy, it could sort all the warmer particles of gas in a chamber to one side and all the cold particles to the other. It would be almost like getting heat from thin air, an immense source of energy at virtually no cost. Maxwell recognized that such a process would border on violating the Second Law of Thermodynamics, which states, in essence, that entropy wins in the end, that things tend not to assume a more complex, orderly form unless energy is added to them. Since filtering—a far cry from robotically conquering the world—is what nanoparticles currently do best, Maxwell's Demon is not such a far-fetched application.

In the meantime, Leigh contents himself with miracles like making water droplets run uphill, thanks to tiny, twisting "motors" created by simple chemical reactions between a few atoms. Similarly, the Livingston-based company Memsstar is creating more efficient surfaces for industrial coatings and wafers by, for instance, finding ways to keep them dry with microscopic gyroscopes. Leigh recognizes that this is "complete sci-fi stuff," but he suggests it's a wonder we haven't made more use of such processes before. "Nature uses molecular machines to do everything ... every single biological process," he says. "We used controlled molecular motion for nothing. Nature isn't using it for nothing. When mankind learns to make molecular machines, it's going to change everything."

He expects that revolution within a decade. Being able to design surfaces at the molecular level increasingly means being able to alter them on cue at the molecular level. "You can make surfaces that change their properties, so you can drag objects toward you just using light," says Leigh. "One day, you might walk into your house to find that the kids have made some big mess, and you just turn on some lasers that put everything back in place." After years of using nanotech for microlevel processes such as more efficiently sorting chemicals, Leigh says, his water droplet stunt "showed that you could use microscopic machines to do things in the real world, the big world."

The staff of Leigh's Edinburgh lab, perhaps as a reminder to remain humble, has put up a poster of actor/singer David Hasselhoff that reads "I tried to save the world and I forgot to save myself.' —The Hoff." Leigh is mindful that for all our fantasies of transforming the outside world, our own bodies are an important locus of nanotech potential. "Nature carries cargo throughout the cells using molecular machines," he says, and that opens up all sorts of possibilities for manipulating the system.

Nanosize Me

Medical uses offer some of the most immediate benefits of improved molecular manipulation. Adam Curtiss, a professor of cell biology at the University of Glasgow's Centre for Cell Engineering, has shown that by restructuring molecules on the surface of stem cells—just altering the roughness of the surface, without making chemical or biological changes—scientists can determine what sort of tissue the cells will grow into. Scott Wilson, a senior project manager with Scottish Enterprise, enthuses that nanotech may soon allow the easy transfer of signals between wires and nerves. That could be useful in many cybernetic and medical devices, such as more versatile prostheses. A step farther removed from the human body, ArrayJet, a company based in the Midlothian town of Dalkeith, is quietly improving the quality of scientists' microscope slides by using inkjetlike technology to place samples on them with unprecedented accuracy. Meanwhile, the Intermediary Technology Institutes in Glasgow, taking a page from the comic book character Wolverine with his adamantium-plated skeleton, are studying potential reinforcement coatings for osteoporosis-ravaged bones.

In the past people were content simply to imagine such things, says Brendan Casey, chief executive of the Glasgow-based company Kelvin Nanotechnologies, but now "people expect delivery." Delivery, in the case of Casey's company, means fabricating materials in an ultramodern, stray-particle-free "clean room" in an old Victorian building at the University of Glasgow (where, Casey says, you become very adept at recognizing people in their jumpsuits and hoods). Sometimes clients know precisely what materials they need, he says, while other times they'll say, "I'm not even sure if this is possible, but can you do this for me?"

Kelvin Nanotechnologies has been involved in research on so-called "labs on a pill" and "labs on a chip," tiny chemical diagnostic and medicine-delivery devices within the body that eliminate such macroscopic clumsiness as time-release capsules, lengthy probes and the need for many medicines to travel through the entire bloodstream. They employ precise fits between target cells and injected substances that Casey describes as "molecular Lego." The ability to sort substances at the molecular level has applications from water flow in 9-inch pipes to fiber-optic cables. It also will likely mean the ability to regrow injured tendons along grooves created by nanomaterial within the body that melt away after use.

At the University of St. Andrews, the scientists of the Biophotonics Programme, aided by the fact that sufficiently small particles can be manipulated by light, are working with lasers as optical tweezers—the "ultimate sterile instrument," one researcher calls them. Such instruments could decrease the odds of hospital infections by moving cells and microscopic dollops of medicine without the need for contact between flesh and solid instruments. Sufficiently fine-tuned tweezing, of a sort impossible with larger tools made from metal, may make it possible to deactivate tumors by identifying and destroying their stem cells. St. Andrews physicist Kishan Dholakia has high hopes for using molecular sorting and lasers to make more diagnoses at the chemical level rather than through patient observation.

Rather than looking at macroscopic phenomena, doctors of the future may be able to tag, track and observe the cellular-level damage that is causing problems, whether it's a perforated spleen or a misfiring nerve in the lower back. If that sounds too distant and speculative, St. Andrews researchers are already working with light-activated creams that speed wound healing and are less likely to leave scars than conventional bandages and stitches.

Defense of Mechanisms

Wonderful as all this is, it is gradual and piecemeal—not as frightening, terrible or transformative as either the sci-fi optimists or the doom-saying activists would have it. And that makes it all the more ridiculous that such valuable work might be impeded by regulations or protests motivated by mostly imaginary or far-off scenarios. One reason the Scots are so optimistic about their potential to be big players in nanotech is their belief that wariness about cloning and stem cell research in the United States and a general aversion to biotechnology in continental Europe do not bode well for nanotech research in those places.

Friends of the Earth and Greenpeace, along with various European green groups, have called for a moratorium on nanotech until it can be proven safe. At their urging, the European Commission last year began to consider whether nanotech fits under existing E.U. safety regulations or must be subjected to special reviews and controls. This sort of legal limbo tends to inhibit investment.

In the United States, the Food and Drug Administration (FDA) regards nanotech as a "combination product" that bridges the divide between pharmaceuticals, biological agents and medical devices. That means nanotech must be proven safe and effective before approval and may risk being shuttled between different offices, but is not as yet presumed especially dangerous. The FDA concedes it has no regulatory authority over nondrug, nonfood products such as nanotech-incorporating cosmetics, a frequent target of unscientific health scares. It would not be surprising if the FDA eventually invites discussion of whether to expand its regulatory authority to cover nanotech uses currently outside its bailiwick or cedes such regulatory responsibility to other agencies. In 2006 the Berkeley City Council, often in the vanguard of green regulations, became the first U.S. locality to explicitly require tracking of production processes involving nanoparticles.

While nanotech has not yet attracted as much ire as biotech, nanotech researchers are worried by the negative tone of much of the press coverage biotech receives. Shortly before my visit to Scotland, the Roslin Research Institute—a source of Midlothian pride 11 years ago when it unveiled the cloned sheep Dolly—declined to participate in a BBC special about biotech because it was clear the show would take a "Frankenstein unleashed" approach, according to Harry Griffin, the institute's former science director and CEO. I saw an ad for the broadcast, an episode of the BBC series Animal Farm , while I was in Scotland. In the sort of overt appeal to ignorance that has become the norm in media coverage of biotechnology, it suggested that what viewers don't know about high-tech animal husbandry should be cause for alarm.

Among those making a conscious effort to stave off similar paranoia about nanotech are Richard Moore and Ottilia Saxl of the Institute of Nanotechnology in Stirling. Moore laments green activists' "tendency to consider any of the risks and not the benefits." He likens the recklessness of being overcautious about nanotechnology to regulators' longtime resistance to portable defibrillators, once feared because of their potential misuse in inexpert hands but now so valued in the U.K. that they are routinely carried on garbage trucks and kept in other widespread places to make their rapid deployment possible. "There's no medical device that's free of risk," he notes.

Suppose "you've got a disseminated brain tumor, and you're offered nanoparticles or you've got three weeks to live," says Saxl. "If you can actually minutely target these nanoparticles at the tumor, what a wonderful thing." She has helped organize awareness-raising conferences on "bioinspired nanotechnologies" and nanotech's environmental benefits (such as radically more efficient oil spill cleanups) because the sense that nanotech is "unnatural" could make it the next target of green or Luddite revulsion. "Lipids and other natural substances can be called nanoparticles," she notes, "but companies didn't want to call their work nanotechnology."

Moore adds that people tend to assume that "natural" things are safe and that the products of industry are automatically a cause for concern. "We're talking about man-made nanoparticles," he says, "but we've had natural nanoparticles for centuries"—from volcanoes and other natural sources, spewed far and wide—with little concern except among those directly in the blast zone.

No Pants, No Implants

In the United States, despite our flirtation with paranoia about biotech and our routine panics over pharmaceuticals and industrial chemicals, our resilient gee-whiz attitude toward machines may yet make the country a haven for unbounded nanotech. But be watchful of those who seek to smother it as a potential monster long before it has had a chance to yield anything remotely resembling the dreams of the optimists or the nightmares of the detractors.

Given people's instinctive unease about strange things entering their bodies, we may be better off if consumers become enamored of relatively trivial nanotech applications, such as the now-omnipresent stain-resistant pants, before taking much notice of the far more beneficial medical uses. Biotech endures in the United States largely because people are accustomed to seeing it used in corn, soybeans, wheat and other staples of the food supply before opponents had really spread their message. Similarly, we may find that a nation long accustomed to unnaturally clean pants is more receptive to nano-based treatments for cancer and Parkinson's.

Today's researchers can only dream of someday possessing the technology to make self-construction by nanobots more efficient than a macroscopic process for making nanobots. Only then could they begin to dream of making the self-construction process propagate itself so rapidly that it constituted a widening menace. Worrying at this stage about the theoretical potential for nanotech to destroy the world—or to transform us into shape-shifting gods—is a bit like worrying that if we engage in laser research we might someday create a laser weapon so powerful that it could destroy the entire planet. There's a long way between here and there, and those distant prospects should not cause us to hobble people taking tiny steps in far more benign directions.

Todd Seavey is a Phillips Foundation Journalism Fellow and the editor of HealthFactsAndFears.com.

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