Chapter 2: Building Blocks
32 - El Nano (Part Three)
By 2002 Japan was spending more on small-tech research and development than any other country, but the race for microscopic supremacy was clearly on: Between 1997 and 2002, nanotech R&D spending in China and Australia grew from none to $40 million; and in Taiwan and South Korea it grew from none to $70 million and $100 million, respectively. During the same period it increased 175 percent, to over $350 million, in western Europe and by 40 percent, to $604 million, in the United States. Meanwhile Japan multiplied its investment by 525 percent, to $750 million. For 2004, U.S. federal funding rose to $847 million, and the recently passed 21st Century Nanotechnology Research and Development Act spreads another $3.7 billion over the four years beginning in 2005. U.S. officials see the sale of nanotech products reaching $1 trillion by 2015. Small wonder that when the European research firm CMP Científica released a nanotech market analysis in 2002, they called their study “a snapshot of an explosion.”
Much of the U.S. funding flows through agencies ranging from the Department of Energy to NASA to the Environmental Protection Agency. But additional large sums pass through the Department of Defense, especially its high-tech brain trust DARPA—the Defense Advanced Research Projects Agency—which is a major developer of such fields as distributed nano-sensors for battlefields and civil defense, nano-filters for biowar agents, nanoscale computers, and biomolecular body armors. The book Nanotechnology and Homeland Security
Toward the end of his life, Smalley warned that military involvement in nanotech opens a new frontier of risk. “Technology that turns out miniature computers could also be used to create miniature weapons,” he said. And that will give rise to threats we are only beginning to comprehend. If we can program invisible nanobots to scrub plaque from arteries, for instance, they can also be programmed to kill. One expert worries that nano-computers that can lodge inside our brains could make us all love Big Brother. (This is not out of the question. For example, there are parasites that lodge in fish brains with similar effect: they cause the fish to behave in ways that make them vulnerable to a predator crucial to the parasites’ life cycle. Other research has shown that nanoparticles placed in a human nose soon find their way into the brain.)
Of more immediate concern is a study in which DuPont researchers injected nanotubes into the lungs of lab rats. The animals soon began gasping for breath, and 15 percent of them died. An alarm has also been raised by a University of Liverpool pathologist whose work suggests that how small a particle is will play a much greater role than the material it’s made of in determining whether it’s hazardous. Says Pat Roy Mooney, executive director of ETC, a technology watchdog group, “Particles of that size can go anywhere they please. They pass the entire immune system. They can pass the blood-brain barrier; they can go into the spinal cord.” Real concern is warranted, if so far largely unaddressed. Of the roughly $1 billion spent on nanotech R&D in 2003, less than 1 percent went for the study of toxic side effects.
And there is the infamous “gray goo” scenario cherished by sci-fi fans. In that scheme, self-replicating nanomachines get out of control and proliferate wildly until they blanket the earth. Regarding gray goo, writer Paul Marks notes, “Many might argue that a self-replicating nanoscale machine—human DNA—is already doing its damnedest to suffocate the planet.” This notwithstanding, a gray goo catastrophe is unlikely anytime soon. In fact a number of scientists, Smalley prominent among them, have expressed doubts that assembling things atom by atom will ever produce self-replicating devices, or commercial products of any kind. Controlling things at atomic scale, they say, will simply cost too much and take too long. Michael Gross of Oxford University’s Centre for Molecular Sciences joins them, raising the specter of the 2nd Law. “Assemblers can’t just crawl around the nanoworld ordering atoms in the way we want them without creating some disorder in the exchange,” he explains. “The natural tendency toward a disordered state would make this very difficult.”
Beyond, or perhaps beneath, such concerns there are philosophical issues that also need resolving. Drexler, Merkle, and many of the people they work with envision nano-devices that are still based very much on the machine age model. Those devices, while extraordinary, are not all that different in spirit from nineteenth-century steam engines. The effect the machine age has had on the natural world should give us pause about a nanotechnology guided solely by the machine metaphor.
On the other hand, what if we can do as nature does? All apples, for instance, are the product of molecular assemblers. And they cost virtually nothing. Any apple can make more apples; it needs only soil and good weather. “The structural biology of the cell will be the most important input into nanotechnology,” claims Gross, “definitely more important than positioning atoms. The cell never bothers about putting atoms into place.” It employs what he calls “the modular design principle”—using a set of small molecules that come together like Lego bricks to build something larger, a big molecule like a protein or DNA. That modular principle can go a step further, Gross adds. “Even macromolecules can be building blocks.” And the payoff is that they organize themselves: they have the right shape and binding preferences to form into even-more-complex structures. “The protein factory of the cell,” he notes, “can self-assemble almost magically from a mix of more than fifty different molecular units.”
The idea of mimicking a living cell’s assemblers brings with it limitations. One is that cells tend to function only in water. Using organic parts, Smalley noted, “would greatly limit the range of materials that could be built” while at the same time imposing on the assembler “a long list of vulnerabilities and limitations to what it can do.” But if that point is well taken, it’s also true that the conceptual dynamics of natural logic can have broad application. Duke University’s Steven Vogel, a leading new biologist, says, “The smaller the scale [at which bio-mimicry is conducted], the better the prospects for emulation.” And Philip Ball, writing for the journal Nature, remarks:
Fundamental research on the character of nature’s mechanisms, from the elephant to the protein, is sure to enrich the pool from which designers and engineers can draw ideas. The scope for deepening this pool is still tremendous. It is at the molecular scale…that we will surely see the greatest expansion of horizons, as structural studies and single-molecule experiments reveal the mechanics of biomolecules. If any reminder is needed that nanotechnology should not seek to shrink mechanical engineering, cogs and all, to the molecule scale, it is found here.
On the other side of this debate are Drexler, Merkle, and their allies, who remain convinced they have the future in their grasp—a future of nanomechanical devices that can assemble materials into any shape and that will be cheap, easy to make, and inexpensive to operate.
Keeping his feet on what at least for now remains solid ground, Gross says, “I think the brave new world of infinite wealth is still a dream. But even if…a few more generations have to work in traditional factories instead of delegating their work to nanorobots, it would still be helpful if we could develop molecular motors as efficient as our muscles, and data storage devices as compact as DNA.” Nature, he says, has taught us that these can be achieved.
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