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anotechnology will make us healthy andwealthy though not necessarily wise. In a fewdecades, this emerging manufacturing tech-nology will let us inexpensively arrange atomsand molecules in most of the ways permittedby physical law. It will let us make supercom-

puters that fit on the head of a pin and fleets of medical nanoro-bots smaller than a human cell able to eliminate cancer, infec-tions, clogged arteries, and even old age. People will look backon this era with the same feelings we have toward medievaltimes—when technology was primitive and almost everyonelived in poverty and died young.

Besides computers billions of times more powerful thantoday’s, and new medical capabilities that will healand cure in cases that are now viewed as utterlyhopeless, this new and very precise way of fabri-cating products will also eliminatethe pollution from current manu-facturing methods. Molecular man-ufacturing will make exactly what itis supposed to make, no more andno less, and therefore won’t make pollutants.

When nanotechnology pioneer EricDrexler first dared to publish this vision backin the early 1980s, the response was skepti-cal, at best. It seemed too good to be true, andmany scientists pronounced the whole thing impos-sible. But the laws of physics care little for either ourhopes or our fears, and subsequent analysis keptreturning the same answer: it will take time, but it isnot only possible but almost unavoidable.

The progress of technology around the world hasalready given us more precise, less expensive manu-facturing technologies that can make an unprece-dented diversity of new products. Nowhere is thismore evident than in computer hardware: computa-tional power has increased exponentially while thefinest feature sizes have steadily shrunk into the deepsubmicron range. Extrapolating these remarkably reg-ular trends, it seems clear where we’re headed: molec-ular computers with billions upon billions ofmolecular switches made by the pound. Andif we can arrange atoms into molecu-lar computers, why not a whole

range of other molecularly precise products?It has taken decades for the bulk of the research community

to accept the feasibility of this vision. But when the President ofthe United States in January 2000 called for a US $500 millionNational Nanotechnology Initiative, we knew nanotechnologyhad reached critical mass.

Visions of good, visions of harm

Some people have recently, publicly (and belatedly) realizedthat nanotechnology might create new concerns that we shouldaddress. Any powerful technology can be used to do great harmas well as great good. If the vision of nanotechnology sketched

earlier is even partly right, we are in forsome major changes—as big as the changes

ushered in by the Industrial Revolution, if notbigger. How should we deal with these changes?

What policies should we adopt during the develop-ment and deployment of nanotechnology?

Drexler discussed these issues extensively in his1986 book Engines of Creation, and, in a remarkablyprescient essay first published in 1988, called “A Dia-log on Dangers,” outlined the concerns that have sincecome to the fore. One solution to these potential prob-lems, proposed by Bill Joy, cofounder and chief scien-tist of Sun Microsystems Inc., would be to “relinquish”research and development of nanotechnology to avoidany possible adverse consequences.

This approach suffers from major problems:telling researchers not to research nanotechnologyand companies not to build it when there are vastfortunes to be made, glory to be won, and nationalstrategic interests at stake either won’t work, or willpush research underground where it can’t be regu-lated. At the same time, it will deprive anyone whoactually obeys the ban of the many benefits nan-otechnology offers.

If a ban won’t work, how should we best address theconcerns that have been raised? The key concerns fallinto two classes: deliberate abuse and accidents.

Deliberate abuse, the misuse of a technology bysome small group or nation to cause great

harm, is best prevented by measures basedon a clear understanding of that tech-

Nanotechnology: What Will It Mean?BY R ALPH C. MERKLE Zyvex Corp.

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complex, planar, micron-scale parts made with lithographic tech-nology and assemble those planar parts into simple three-dimen-sional robotic arms that have the ability to pick up speciallydesigned MEMS parts. Called exponential assembly, this replica-tive technology starts with a single robotic arm on a wafer thatthen assembles more robotic arms on a facing wafer by picking

up parts already laid out in precisely known locations. While the number of assembled robotic arms can increase

exponentially (up to some limit imposed by the manufactur-ing system), this assembly process requires (among otherthings) lithographically produced parts, as well as externallyprovided power and computer control signals to coordinate thecomplex motions of the robotic arms. Cut off from power,control signals, and parts, a micron-sized robotic arm wouldfunction about as well as one of its larger cousins taken from

one of today’s automated assembly linesand dropped into the middle of a forest.

Guidelines to principled developmentTo avoid any possible risk from future(and perhaps more ambitious) systems,the Palo Alto–based nonprofit ForesightInstitute (motto: preparing for nan-otechnology) has written a set of draft

guidelines to inform developers and manufacturers ofmolecular manufacturing systems how to develop themsafely. The guidelines include such common sense princi-ples as: artificial replicators must not be capable of repli-cation in a natural, uncontrolled environment; they musthave an absolute dependence on an artificial fuel source orartificial components not found in nature; they must useappropriate error detection codes and encryption to preventunintended alterations in their blueprints; and the like.

Building on over a decade of discussions of a very widerange of scenarios, the first version of the guidelines wasbased on a February 1999 workshop in Monterey, Calif. Theguidelines have since been reviewed at two subsequentForesight conferences. Because our understanding of thisdeveloping technology is evolving, and will continue to doso, the guidelines will evolve with them—representing ourbest understanding of how to ensure the safe developmentof nanotechnology.

Nanotechnology’s potential to improve the human condi-tion is staggering: we would be shirking our duty to future gen-erations if we did not responsibly develop it. •

nology. Nanotechnology could, in the future, be used to rapidlyidentify and block attacks. Distributed surveillance systemscould quickly identify arms buildups and offensive weaponsdeployments, while lighter, stronger, and smarter materialscontrolled by powerful molecular computers would let usmake radically improved versions of existing weapons able torespond to such threats. Replicat-ing manufacturing systems couldrapidly churn out the neededdefenses in huge quantities. Suchsystems are best developed by con-tinuing a vigorous R&D program,which provides a clear understand-ing of the potential threats andcountermeasures available.

Besides deliberate attacks, theother concern is that a self-replicating molecular machinecould replicate unchecked, converting most of the biosphereinto copies of itself.

While nanotechnology does propose to use replication (toreduce manufacturing costs to a minimum), it does not pro-pose to copy living systems. Living systems are wonderfullyadaptable and can survive in a complex natural environment.Instead, nanotechnology proposes to build molecular machinesystems that are similar to small versions of what you might

find in today’s modern factories. Robotic arms shrunk to sub-micron size should be able to pick up and assemble molecu-lar parts like their large cousins in factories around the worldpick up and assemble nuts and bolts.

Unfortunately, our intuitions about replicating systemscan be led seriously astray by a simple fact: the only replicat-ing systems most of us are familiar with are biological self-repli-cating systems. We automatically assume that nanotechno-logical replicating systems will be similar when, in fact, nothingcould be further from the truth. The machines people makebear little resemblance to living systems, and molecular man-ufacturing systems are likely to be just as dissimilar.

An illustration of the vast gulf between self-replicating bio-logical systems and the kind of replicating robotic systems thatmight be made for manufacturing purposes is exponentialassembly, a technology currently under investigation at our com-pany, Zyvex Corp., in Richardson, Texas. Zyvex is developing posi-tional assembly systems at the micron, submicron, and molec-ular scale. At the micron scale, using existing MEMS(microelectromechanical systems) technology, we are developingsimple pick-and-place robotic arms that can pick up relatively

“Telling researchers not to research nanotechnology and companies not to build it when there are fortunes to be made…will push research underground where it can’t be regulated”

“Nanotechnology’s potential to improve thehuman condition is staggering: we would beshirking our duty to future generations if we did not responsibly develop it”