Safe Utilization of Advanced Nanotechnology

Many words have been written about the dangers of advanced nanotechnology. Most of the threatening scenarios involve tiny manufacturing systems that run amok, or are used to create destructive products. A manufacturing infrastructure built around a centrally controlled, relatively large, self-contained manufacturing system would avoid these problems. A controlled nanofactory would pose no inherent danger, and it could be deployed and used widely. Cheap, clean, convenient, on-site manufacturing would be possible without the risks associated with uncontrolled nanotech fabrication or excessive regulation. Control of the products could be administered by a central authority; intellectual property rights could be respected. In addition, restricted design software could allow unrestricted innovation while limiting the capabilities of the final products. The proposed solution appears to preserve the benefits of advanced nanotechnology while minimizing the most serious risks.

Advanced Nanotechnology And Its Risks

As early as 1959, Richard Feynman proposed building devices with each atom precisely placed1. In 1986, Eric Drexler published an influential book, Engines of Creation2, in which he described some of the benefits and risks of such a capability. If molecules and devices can be manufactured by joining individual atoms under computer control, it will be possible to build structures out of diamond, 100 times as strong as steel; to build computers smaller than a bacterium; and to build assemblers and mini-factories of various sizes, capable of making complex products and even of duplicating themselves.

Drexler's subsequent book, Nanosystems3, substantiated these remarkable claims, and added still more. A self-contained tabletop factory could produce its duplicate in one hour. Devices with moving parts could be incredibly efficient. Molecular manufacturing operations could be carried out with failure rates less than one in a quadrillion. A computer would require a miniscule fraction of a watt and one trillion of them could fit into a cubic centimeter. Nanotechnology-built fractal plumbing would be able to cool the resulting 10,000 watts of waste heat. It seems clear that if advanced nanotechnology is ever developed, its products will be incredibly powerful.

As soon as molecular manufacturing was proposed, risks associated with it began to be identified. Engines of Creation2 described one hazard now considered unlikely, but still possible: grey goo. A small nanomachine capable of replication could in theory copy itself too many times4. If it were capable of surviving outdoors, and of using biomass as raw material, it could severely damage the environment5. Others have analyzed the likelihood of an unstable arms race6, and many have suggested economic upheaval resulting from the widespread use of free manufacturing7. Some have even suggested that the entire basis of the economy would change, and money would become obsolete8.

Sufficiently powerful products would allow malevolent people, either hostile governments or angry individuals, to wreak havoc. Destructive nanomachines could do immense damage to unprotected people and objects. If the wrong people gained the ability to manufacture any desired product, they could rule the world, or cause massive destruction in the attempt9. Certain products, such as vast surveillance networks, powerful aerospace weapons, and microscopic antipersonnel devices, provide special cause for concern. Grey goo is relevant here as well: an effective means of sabotage would be to release a hard-to-detect robot that continued to manufacture copies of itself by destroying its surroundings.

Clearly, the unrestricted availability of advanced nanotechnology poses grave risks, which may well outweigh the benefits of clean, cheap, convenient, self-contained manufacturing. As analyzed in Forward to the Future: Nanotechnology and Regulatory Policy10, some restriction is likely to be necessary. However, as was also pointed out in that study, an excess of restriction will enable the same problems by increasing the incentive for covert development of advanced nanotechnology. That paper considered regulation on a one-dimensional spectrum, from full relinquishment to complete lack of restriction. As will be shown below, a two-dimensional understanding of the problem—taking into account both control of nanotech manufacturing capability and control of its products—allows targeted restrictions to be applied, minimizing the most serious risks while preserving the potential benefits.

Nanotech Manufacturing and Its Products

The technology at the heart of this dilemma is molecular manufacturing. A machine capable of molecular manufacturing—whether nanoscale or macroscale—has two possible functions: to create more manufacturing capacity by duplicating itself, and to manufacture products. Most products created by molecular manufacturing will not possess any capacity for self-duplication, or indeed for manufacturing of any kind; as a result, each product can be evaluated on its own merits, without worrying about special risks. A nanotechnology-based manufacturing system, on the other hand, could build weapons, grey goo, or anything else it was programmed to produce. The solution, then, is to regulate nanofactories; products are far less dangerous. A nanotechnology-built car could no more turn into grey goo than a steel-and-plastic car could.

Some products, however, will be powerful enough to require restriction. Weapons built by nanotechnology would be far more effective than today's versions. Very small products could get lost and cause nano-litter, or be used to spy undetectably on people. And a product that included a general molecular manufacturing capability would be, effectively, an unregulated nanofactory—horrifyingly dangerous in the wrong hands. Any widespread use of nanotechnology manufacturing must include the ability to restrict, somehow, the range of products that can be produced.

If it can be done safely, widespread use of molecular manufacturing looks like a very good idea for the following reasons:
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The ability to produce duplicate manufacturing systems means that manufacturing capacity could be doubled almost for free.
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A single, self-contained, clean-running personal nanofactory could produce a vast range of strong, efficient, carbon-based products as they are needed.
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Emergency and humanitarian aid could be supplied quickly and cheaply.
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Many of the environmental pressures caused by our current technology base could be mitigated or removed entirely.
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The rapid and flexible manufacturing cycle will allow many innovations to be developed rapidly.

Although a complete survey and explanation of the potential benefits of nanotechnology is beyond the scope of this paper, it seems clear that the technology has a lot to offer.

All of these advantages should be delivered as far as is consistent with minimizing risks. Humanitarian imperatives and opportunities for profit both demand extensive use of nanotechnology. In addition, failure to use nanotechnology will create a pent-up demand for its advantages, which will virtually guarantee an uncontrollable black market. Once molecular manufacturing has been developed, a second, independent development project would be both far easier and far more dangerous than the original project. The first nanofactory must be made available for widespread use to reduce the impetus for independent development11.

Development of nanotechnology must be undertaken with care to avoid accidents; once a nanotechnology-based manufacturing technology is created, it must be administered with even more care. Irresponsible use of molecular manufacturing could lead to black markets, unstable arms races ending in immense destruction, and possibly a release of grey goo. Misuse of the technology by inhumane governments, terrorists, criminals, and irresponsible users could produce even worse problems—grey goo is a feeble weapon compared to what could be designed. It seems likely that research leading to advanced nanotechnology will have to be carefully monitored and controlled.

However, the same is not true of product research and development. The developer of nanotechnology-built products does not need technical expertise in nanotechnology. Once a manufacturing system is developed, product designers can use it to build anything from cars to computers, simply by reusing low-level designs that have previously been developed. A designer may safely be allowed to play with pieces 1,000 atoms on a side (one billion atoms in volume). This is several times smaller than a bacterium and 10,000,000 times smaller than a car.

Working with modular “building blocks” of this size would allow almost anything to be designed and built, but the blocks would be too big to do the kind of molecular manipulation that is necessary for nano-manufacturing or to participate in biochemical reactions. A single block could contain a tiny motor or a computer, allowing products to be powered and responsive. As long as no block contained machinery to do mechanochemistry, the designer could not create a new kind of nanofactory.

Once designed and built, a product of molecular manufacturing could be used by consumers just like a steel or plastic product. Of course, some products, such as cars, knives, and nail guns, are dangerous by design, but this kind of danger is one that we already know how to deal with. In the United States, Underwriter's Laboratories (UL), the Food and Drug Administration, and a host of industry and consumer organizations work to ensure that our products are as safe as we expect them to be. Nanotechnology products could be regulated in the same way. And if a personal nanofactory could only make approved products, it could be widely distributed, even for home use, without introducing any special risks.

Nanofactory Technology: Regulating Risk, Preserving Benefit

It is generally assumed, incorrectly, that devices built with nanotechnology must be quite small. This has led to fears that molecular manufacturing systems will be hard to control and easy to steal. In fact, as analyzed by Drexler and others in the field, the products of nanoscale mechanochemical plants can be attached together within the enclosure of a single device. Small building blocks can be joined to make bigger blocks; these blocks can be joined with others, and so on to form a product. This process is called convergent assembly, and it allows the creation of large products from nanoscale parts. In particular, convergent assembly will allow one nanofactory to build another nanofactory. There is no need to use trillions of free-floating assembler robots; instead, the assemblers—now called fabricators—are securely fastened inside the factory device, where they feed the smallest conveyor belts.

A typical personal nanofactory (PN) might be the size of a microwave oven. Since the fabricators are fastened into the factory and dependent on its power grid, they have no need to navigate around the product they are building—this improves efficiency—and they have no chance of functioning independently. In addition, the entire nanofactory can be controlled through a single interface, which allows restrictions to be built into the interface. It can simply refuse to produce any product that has not been approved. (The improved security of tethered nanotechnology factories has been a theme in at least one work of science fiction12.)

If a PN will only build safe products, and will refuse to build any product that has not been approved as safe, then the factory itself can be considered safe. It could even build a duplicate PN on request. With the restrictions built in, the second one would be as safe as the first. As long as the restrictions work as planned, there is no risk of grey goo, no risk of undesirable weapons or unapproved products, and no risk of producing unrestricted nanofactories that could be used to make bad products.

At the same time, products that were approved could be produced in any quantity desired. The products could even be customized, within limits—and the limits could be quite broad, for some kinds of products. If desired, the PNs (and the products) could have tracking devices built in to further deter inappropriate use.

With personal nanofactories that can only produce approved designs, the safety of molecular manufacturing does not depend on restricting the use of the factories. Instead, it depends on choosing correctly which products to approve. The nanofactory itself, as a product, can be approved for unlimited copying. This means that the abundant, cheap, and convenient production capability of advanced nanotechnology can be achieved without the risks associated with uncontrolled molecular manufacturing. A two-dimensional view of the risks of nanotechnology, which separates the means of production from the products, allows the design and implementation of policy that is minimally restrictive, yet still safe.

Using Nanotechnology Safely

A safe personal nanofactory design must build approved products, while refusing to build unapproved products. It must also be extremely tamper-resistant; if anyone found a way to build unapproved products, they could make an unrestricted, unsafe nanofactory, and distribute copies of it. The product approval process must also be carefully designed, to maximize the benefits of the technology while minimizing the risk of misuse. Restricted nanofactories avoid the extreme risk/benefit tradeoff of other nanotechnology administration plans, but they do require competent administration.

One way to secure a personal nanofactory is to build in only a limited number of safe designs. The user could ask it to produce any one of those designs, but with no way to feed in more blueprints, the factory could never build anything else. This simple scheme is fairly reliable, but not very useful. It also poses the risk that someone could take apart the factory and find a way to reprogram its design library.

A more useful and secure scheme would be to connect the PN to a central controller, and require it to ask for permission each time it was asked to manufacture something. This would allow new designs to be added to the design library after the nanofactory was built. In addition, the PN would have to report its status back to the central controller. The system could even be designed to require a continuous connection; a factory disconnected from the network would permanently disable itself.

This would greatly reduce the opportunity to take the factory apart, since it could report the attempt in real time, and failed attempts would result in immediate arrest of the perpetrator. This permanent connection would also allow the factory to be disabled remotely if a security flaw were ever discovered in that model. Finally, a physical connection would allow the location of the factory to be known, and jurisdictional limits to be imposed on its products.

Current cryptographic techniques permit verification and encryption of communication over an unsecured link. These are used in smart cards and digital cellular phones, and will soon be used in digital rights management13. Using such techniques, each personal nanofactory would be able to verify that it was in communication with the central library. Only designs from the library could be manufactured. In addition, each design could come with a set of restrictions. For example, medical tools might only be manufactured at the request of a doctor. Commercial designs could require payment from a user. Designs under development could be manufactured only by the inventor, until they were approved and released. A design that did not come from the central library would not have the proper cryptographic signature, and the factory would simply refuse to build it.

Product Design Parameters

Rapid innovation is a key benefit of nanotechnology. The rapid and flexible manufacturing process allows a design to be built and tested almost immediately. Because designers of nano-built products do not have to do any actual nanotechnology research, a high level of innovation can be accommodated without giving designers any access to dangerous kinds of products. As mentioned above, a design with billion-atom, sub-micron blocks—permitting specification of near-biological levels of complexity—would still pose no risk of illicit self-replication. The minimum building block size in a design could be restricted by the design system. A fully automated evaluation and approval process could also consider the energy and power contained in the design, its mechanical integrity, and the amount of computer power built in. The block-based design system provides a simple interface to the block-based convergent assembly system. A variety of design systems could be implemented using the same nanofactory hardware, and the designer would not have to become an expert on the process of construction to create buildable designs.

With a safe-design personal nanofactory, adults—and even children—could safely play with advanced robotics, inventing and constructing almost anything they could imagine. (Today, adults as well as children find it worthwhile to play with the Lego MindStorms™ system14.) More powerful products would require an engineering certification. This could be given to any responsible adult, since even a malicious product engineer would be unable to bypass the factory's programming and cause it to make illicit fabricators. A product that included chemical or nanomechanical manipulation ability would have to be carefully controlled, even during the design phase, to prevent the designer from building something that could be used for illicit nanomanufacturing.

Risks and dangers associated with products could be assessed on a per-product basis. Many products, produced with simplified design kits, could be approved with only automated analysis of their design. Most others could be approved after a safety and efficacy assessment similar to today's approval processes. Only rarely would a new degree of nanotechnological functionality be required, so each case could be carefully assessed before the functionality was added to appropriately restricted design programs.

Product approval for worldwide availability could depend on any of several factors. First, unless designed with a child-safe design program, it could be evaluated for engineering safety. Second, if the design incorporated intellectual property, the owner of the property could specify licensing terms. Third, local jurisdictional restrictions could be imposed, tagging the file according to where it could and could not be manufactured. Finally, the design would be placed in the global catalog, available for anyone to use.

Nanotechnology offers the ability to build large numbers of products that are incredibly powerful by today's standards. This possibility creates both opportunity and risk. The problem of minimizing the risk is not simple; excessive restriction creates black markets, which in this context implies unrestricted nano fabrication. Selecting the proper level of restriction is likely to pose a difficult challenge.

control of the molecular manufacturing capacity, and control of the products. Such a system has many advantages. A well-controlled manufacturing system can be widely deployed, allowing distributed, cheap, high-volume manufacturing of useful products and even a degree of distributed innovation. The range of possible nanotechnology-built products is almost infinite. Even if allowable products were restricted to a small subset of possible designs, it would still allow an explosion of creativity and functionality.

Preventing a personal nanofactory from building unapproved products can be done using technologies already in use today. It appears that the nanofactory control structure can be made virtually unbreakable. Product approval, by contrast, depends to some extent on human institutions. With a block-based design system, many products can be assessed for degree of danger without the need for human intervention; this reduces subjectivity and delay, and allows people to focus on the few truly risky designs.

In addition to preventing the creation of unrestricted molecular manufacturing devices, further regulation will be necessary to preserve the interests of existing commercial and military institutions. For example, the effects of networked computers on intellectual property rights have created concern in several industries15, and the ability to fabricate anything will surely increase the problem. National security will demand limits on the weapons that can be produced

The Silicon Valley Faire

The tour of the molecular world showed some products of molecular manufacturing, but didn't show how they were made. The technologies you remember from the old days have mostly been replaced—but how did this happen? The Silicon Valley Faire is advertised as "An authentic theme park capturing life, work, and play in the early Breakthrough years." Since "work" must include manufacturing, it seems worth a visit.

A broad dome caps the park — "To fully capture the authentic sights, sounds, and smells of the era," the tourguide politely says. Inside, the clothes and hairstyles, the newspaper headlines, the bumper-to-bumper traffic, all look much as they did before your long nap. A light haze obscures the buildings on the far side of the dome, your eyes burn slightly, and the air smells truly authentic.

The Nanofabricators, Inc., plant offers the main display of early nanotechnology. As you near the building, the tourguide mentions that this is indeed the original manufacturing plant, given landmark status over twenty years ago, then made the centerpiece of the Silicon Valley Faire ten years later, when . . . With a few taps, you reset the pocket tourguide to speak up less often.

Pocket Libraries

As people file into the Nanofabricator plant, there's a moment of hushed quiet, a sense of walking into history. Nanofabricators: home of the SuperChip, the first mass-market product of nanotechnology. It was the huge memory capacity of SuperChips that made possible the first Pocket Library.

This section of the plant now houses a series of displays, including working replicas of early products. Picking up a Pocket Library, you find that it's not only the size of a wallet, but about the same weight. Yet it has enough memory to record every volume in the Library of Congress—something like a million times the capacity of a personal computer from 1990. It opens with a flip, the two-panel screen lights up, and a world of written knowledge is at your fingertips. Impressive.

"Wow, can you believe these things?" says another tourist as he fingers a Pocket Library. "Hardly any video, no 3-D–just words, sound, and flat pictures. And the cost! I wouldn't have bought `em for my kids at that price!"

Your tourguide quietly states the price: about what you remember for a top-of-the-line TV set from 1990. This isn't the cheap manufacturing promised by mature nanotechnology, but it seems like a pretty good price for a library. Hmm . . . how did they work out the copyrights and royalties? There's a lot more to this product than just the technology . . .

Nanofabrication

The next room displays more technology. Here in the workroom where SuperChips were first made, early nanotech manufacturing is spread out on display. The whole setup is surprisingly quiet and ordinary. Back in the 1980s and 1990s, chip plants had carefully controlled clean rooms with gowns and masks on workers and visitors, special workstations, and carefully crafted air flows to keep dust away from products. This room has none of that. It's even a little grubby.

In the middle of a big square table are a half-dozen steel tanks, about the size and shape of old-fashioned milk cans. Each can has a different label identifying its contents: MEMORY BLOCKS, DATA-TRANSMISSION BLOCKS, INTERFACE BLOCKS. These are the parts needed for building up the chip. Clear plastic tubes, carrying clear and tea-colored liquids, emerge from the mouths of the milk cans and drape across the table. The tubes end in fist-sized boxes mounted above shallow dishes sitting in a ring around the cans. As the different liquids drip into each dish, a beater like a kitchen mixer swirls the liquid. In each dish, nanomachines are building SuperChips.

A Nanofab "engineer," dressed in period clothing complete with name badge, is setting up a dish to begin building a new chip. "This," he says, holding up a blank with a pair of tweezers, "is a silicon chip like the ones made with pre-breakthrough technology. Companies here in this valley made chips like these by melting silicon, freezing it into lumps, sawing the lumps into slices, polishing the slices, and then going through a long series of chemical and photographic steps. When they were done, they had a pattern of lines and blobs of different materials on the surface. Even the smallest of these blobs contained billions of atoms, and it took several blobs working together to store a single bit of information. A chip this size, the size of your fingernail, could store only a fraction of a billion bits. Here at Nanofab, we used bare silicon chips as a base for building up nanomemory. The picture on the wall here shows the surface of a blank chip: no transistors, no memory circuits, just fine wires to connect up with the nanomemory we built on top. The nanomemory, even in the early days, stored thousands of billions of bits. And we made them like this, but a thousand at a time–" He places the chip in the dish, presses a button, and the dish begins to fill with liquid.

"A few years latter," he adds, "we got rid of the silicon chips entirely"—he props up a sign saying THIS CHIP BUILD BEGAN AT: 2:15 P.M., ESTIMATED COMPLETION TIME: 1:00 A.M.—" and we sped up the construction process by a factor of a thousand."

The chips in the dishes all look pretty much the same except for color. The new chip looks like dull metal. The only difference you can see in the older chips, further along in the process, is a smooth rectangular patch covered by a film of darker material. An animated flowchart on the wall shows how layer upon layer of nanomemory building blocks are grabbed from solution and laid down on the surface to make that film. The tourguide explains that the energy for this process, like the energy for molecular machines within cells, comes from dissolved chemicals—from oxygen and fuel molecules. The total amount of energy needed here is trivial, because the amount of product is trivial: at the end of the process, the total thickness of nanomemory structure—the memory store for a Pocket Library—amounts to one-tenth the thickness of a sheet of paper, spread over an area smaller than a postage stamp.

Molecular Assembly

The animated flowchart showed nanomemory building blocks as big things containing about a hundred thousand atoms apiece (it takes a moment to remember that this is still submicroscopic). The build process in the dishes stacked these blocks to make the memory film on the SuperChip, but how were the blocks themselves built? The hard part in this molecular-manufacturing business has got to be at the bottom of the whole process, at the stage where molecules are put together to make large, complex parts.

The Silicon Valley Faire offers simulations of this molecular assembly process, and at no extra charge. From the tourguide, you learn that modern assembly processes are complex; that earlier processes—like those used by Nanofabricators, Inc.—used clever-but-obscure engineering tricks; and that the simplest, earliest concepts were never built. Why not begin at the beginning? A short walk takes you to the Museum of Antique Concepts, the first wing of the Museum of Molecular Manufacturing.

A peek inside the first hall shows several people strolling around wearing loosely fitting jumpsuits with attached goggles and gloves, staring at nothing and playing mime with invisible objects. Oh well, why not join the fools' parade? Stepping through the doorway while wearing the suit is entirely different. The goggles show a normal world outside the door and a molecular world inside. Now you, too, can see and feel the exhibit that fills the hall. It's much like the earlier simulated molecular world: it shares the standard settings for size, strength, and speed. Again, atoms seem 40 million times larger, about the size of your fingertips. This simulation is a bit less thorough than the last was—you can feel simulated objects, but only with your gloved hands. Again, everything seems to be made of quivering masses of fused marbles, each an atom.

"Welcome," says the tourguide, "to a 1990 concept for a molecular-manufacturing plant. These exploratory engineering designs were never intended for actual use, yet they demonstrate the basics of molecular manufacturing: making parts, testing them, and assembling them."

Machinery fills the hall. Overall, the sight is reminiscent of an automated factory of the 1980s or 1990s. It seems clear enough what must be going on: Big machines stand beside a conveyor belt loaded with half-finished-looking blocks of some material (this setup looks much like Figure 2); the machines must do some sort of work on the blocks. Judging by the conveyor belt, the blocks eventually move from one arm to the next until they turn a corner and enter the next hall.

FIGURE 2: ASSEMBLER WITH FACTORY ON CHIP

A factory large enough to make over 10 million nanocomputers per day would fit on the edge one of today's integrated circuits. Inset shows an assembler arm together with workpiece on a conveyor belt.

Since nothing is real, the exhibit can't be damaged, so you walk up to a machine and give it a poke. It seems as solid as the wall of the nanocomputer in the previous tour. Suddenly, you notice something odd: no bombarding air molecules and no droplets of water—in fact, no loose molecules anywhere. Every atom seems to be part of a mechanical system, quivering thermal vibration, but otherwise perfectly controlled. Everything here is like the nanocomputer or like the tough little gear; none of it resembles the loosely coiled protein or the roiling mass of the living cell.

The conveyor belt seems motionless. At regular intervals along the belt are blocks of material under construction: workpieces. The nearest block is about a hundred marble-bumps wide, so it must contain something like 100 x 100 x 100 atoms, a full million. This block looks strangely familiar, with its rods, crank, and the rest. It's a nanocomputer—or rather, a block-like part of a nanocomputer still under construction.

Standing alongside the pieces of nanocomputer on the conveyor belt, dominating the hall, is a row of huge mechanisms. Their trunks rise from the floor, as thick as old oaks. Even though they bend over, they rear overhead. "Each machine," your tourguide says, "is the arm of a general-purpose molecular assembler.

One assembler arm is bent over with its tip pressed to a block on the conveyor belt. Walking closer, you see molecular assembly in action. The arm ends in a fist-sized knob with a few protruding marbles, like knuckles. Right now, two quivering marbles—atoms—are pressed into a small hollow in the block. As you watch, the two spheres shift, snapping into place in the block with a quick twitch of motion: a chemical reaction. The assembler arm just stands there, nearly motionless. The fist has lost two knuckles, and the block of nanocomputer is two atoms larger.

The tourguide holds forth: "This general-purpose assembler concept resembles, in essence, the factory robots of the 1980s. It is a computer-controlled mechanical arm that moves molecular tools according to a series of instructions. Each tool is like a single-shot stapler or rivet gun. It has a handle for the assembler to grab and comes loaded with a little bit of matter—a few atoms—which it attaches to the workpiece by a chemical reaction." This is like the rejoining of the protein chain in the earlier tour.

Molecular Precision

The atoms seemed to jump into place easily enough; can they jump out of place just as easily? By now the assembler arm has crept back from the surface, leaving a small gap, so you can reach in and poke at the newly added atoms. Poking and prying do no good; when you push as hard as you can (with your simulated fingers as strong as steel), the atoms don't budge by a visible amount. Strong molecular bonds hold them in place.

Your pocket tourguide—which has been applying the power of a thousand 1990s supercomputers to the task of deciding when to speak up—remarks, "Molecular bonds hold things together. In strong, stable materials atoms are either bonded, or they aren't, with no possibilities in between. Assemblers work by making and breaking bonds, so each step either succeeds perfectly or fails completely. In pre-breakthrough manufacturing, parts were always made and put together with small inaccuracies. These could add up to wreck product quality. At the molecular scale, these problems vanish. Since each step is perfectly precise, little errors can't add up. The process either works, or it doesn't."

But what about those definite, complete failures? Fired by scientific curiosity, you walk to the next assembler, grab the tip, and shake it. Almost nothing happens. When you shove as hard as you can, the tip moves by about one-tenth of an atomic diameter, then springs back. "Thermal vibrations can cause mistakes by causing parts to come together and form bonds in the wrong place," the tourguide remarks. "Thermal vibrations make floppy objects bend further than stiff ones, and so these assembler arms were designed to be thick and stubby to make them very stiff. Error rates can be kept to one in a trillion, and so small products can be perfectly regular and perfectly identical. Large products can be almost perfect, having just a few atoms out of place." This should mean high reliability. Oddly, most of the things you've been seeing outside have looked pretty ordinary—not slick, shiny, and perfect, but rough and homey. They must have been manufactured that way, or made by hand. Slick, shiny things must not impress anyone anymore.

Molecular Robotics

By now, the assembler arm has moved by several atom-widths. Through the translucent sides of the arm you can see that the arm is full of mechanisms: twirling shafts, gears, and large, slowly turning rings that drive the rotation and extension of joints along the trunk. The whole system is a huge, articulated robot arm. The arm is big because the smallest parts are the size of marbles, and the machinery inside that makes it move and bend has many, many parts. Inside, another mechanism is at work: The arm now ends in a hole, and you can see the old, spent molecular tool being retracted through a tube down the middle.

Patience, patience. Within a few minutes, a new tool is on its way back up the tube. Eventually, it reaches the end. Shafts twirl, gears turn, and clamps lock the tool in position. Other shafts twirl, and the arm slowly leans up against the workpiece again at a new site. Finally, with a twitch of motion, more atoms jump across, and the block is again just a little bit bigger. The cycle begins again. This huge arm seems amazingly slow, but the standard simulation settings have shifted speeds by a factor of over 400 million. A few minutes of simulation time correspond to less than a millionth of a second of real time, so this stiff, sluggish arm is completing about a million operations per second.

Peering down at the very base of the assembler arm, you can get a glimpse of yet more assembler-arm machinery underneath the floor: Electric motors spin, and a nanocomputer chugs away, rods pumping furiously. All these rods and gears move quickly, sliding and turning many times for every cycle of the ponderous arm. This seems inefficient; the mechanical vibrations must generate a lot of heat, so the electric motors must draw a lot of power. Having a computer control each arm is a lot more awkward now than it was in pre-breakthrough years. Back then, a robot arm was big and expensive and a computer was a cheap chip; now the computer is bigger than the arm. There must be a better way—but then, this is the Museum of Antique Concepts.

Building-Blocks into Buildings

Where do the blocks go, once the assemblers have finished with them? Following the conveyor belt past a dozen arms, you stroll to the end of the hall, turn the corner, and find yourself on a balcony overlooking a vaster hall beyond. Here, just off the conveyor belt, a block sits in a complex fixture. Its parts are moving, and an enormous arm looms over it like a construction crane. After a moment, the tourguide speaks up and confirms your suspicion: "After manufacturing, each block is tested. Large arms pick up properly made blocks. In this hall, the larger arms assemble almost a thousand blocks of various kinds to make a complete nanocomputer.

The grand hall has its own conveyor belt, bearing a series of partially completed nanocomputers. Arrayed along this grand belt is a row of grand arms, able to swing to and fro, to reach down to lesser conveyor belts, pluck million-atom blocks from testing stations, and plug them into the grand workpieces, the nanocomputers under construction. The belt runs the length of the hall, and at the end, finished nanocomputers turn a corner—to a yet-grander hall beyond?

After gazing at the final-assembly hall for several minutes, you notice that nothing seems to have moved. Mere patience won't do: at the rate the smaller arms moved in the hall behind you, each block must take months to complete, and the grand block-handling arms are taking full advantage of the leisure this provides. Building a computer, start to finish, might take a terribly long time. Perhaps as long as the blink of an eye.

Molecular assemblers build blocks that go to block assemblers. The block assemblers build computers, which go to system assemblers, which build systems, which–at least one path from molecules to large products seems clear enough. If a car were assembled by normal-sized robots from a thousand pieces, each piece having been assembled by smaller robots from a thousand smaller pieces, and so on, down and down, then only ten levels of assembly process would separate cars from molecules. Perhaps, around a few more corners and down a few more ever-larger halls, you would see a post-breakthrough car in the making, with unrecognizable engine parts and comfortable seating being snapped together in a century-long process in a hall so vast that the Pacific Ocean would be a puddle in the corner . . .

Just ten steps in size; eight, starting with blocks as big as the ones made in the hall behind you. The molecular world seems closer, viewed this way.

Molecular Processing

Stepping back into that hall, you wonder how the process begins. In every cycle of their sluggish motion, each molecular assembler gets a fresh tool through a tube from somewhere beneath the floor, and that somewhere is where the story of molecular precision begins. And so you ask, "Where do the tools come from?", and the tourguide replies, "You might want to take the elevator to your left."

Stepping out of the elevator and into the basement, you see a wide hall full of small conveyor belts and pulleys; a large pipe runs down the middle. A plaque on the wall says, "Mechanochemical processing concept, circa 1990." As usual, all the motions seem rather slow, but in this hall everything that seems designed to move is visibly in motion. The general flow seems to be away from the pipe, through several steps, and then up through the ceiling toward the hall of assemblers above.

After walking over to the pipe, you can see that it is nearly transparent. Inside is a seething chaos of small molecules: the wall of the pipe is the boundary between loose molecules and controlled ones, but the loose molecules are well confined. In this simulation, your fingertips are like small molecules. No matter how hard you push, there's no way to drive your finger through the wall of the pipe. Every few paces along the pipe a fitting juts out, a housing with a mechanically driven rotating thing, exposed to the liquid inside the pipe, but also exposed to a belt running over one of the pulleys, embedded in the housing. It's hard to see exactly what is happening.

The tourguide speaks up, saying, "Pockets on the rotor capture single molecules from the liquid in the pipe. Each rotor pocket has a size and shape that fits just one of the several different kinds of molecule in the liquid, so the process is rather selective. Captured molecules are then pushed into the pockets on the belt that's wrapped over the pulley there, then—"

"Enough," you say. Fine, it singles out molecules and sticks them into this maze of machinery. Presumably, the machines can sort the molecules to make sure the right kinds go to the right places.

The belts loop back and forth carrying big, knobby masses of molecules. Many of the pulleys—rollers?—press two belts together inside a housing with auxiliary rollers. While you are looking at one of these, the tourguide says, "Each knob on a belt is a mechanochemical-processing device. When two knobs on different belts are pressed together in the right way, they are designed to transfer molecular fragments from one to another by means of a mechanically forced chemical reaction. In this way, small molecules are broken down, recombined, and finally joined to molecular tools of the sort used in the assemblers in the hall above. In this device here, the rollers create a pressure equal to the pressure found halfway to the center of the Earth, speeding a reaction that –"

"Fine, fine," you say. Chemists in the old days managed to make amazingly complex molecules just by mixing different chemicals together in solution in the right order under the right conditions. Here, molecules can certainly be brought together in the right order, and the conditions are much better controlled. It stands to reason that this carefully designed maze of pulleys and belts can do a better job of molecule processing than a test tube full of disorganized liquid ever could. From a liquid, through a sorter, into a mill, and out as tools: this seems to be the story of molecule processing. All the belts are loops, so the machinery just goes around and around, carrying and transforming molecular parts.

Exploring the Molecular World

In the twenty-first century, even more than in the twentieth, it's easy to make things work without understanding them, but to a newcomer much of the technology seems like magic, which is dissatisfying. After a few days, you want to understand what nanotechnology is, on a gut level. Back in the late twentieth century, most teaching used dry words and simple pictures, but now—for a topic like this—it's easier to explore a simulated world. And so you decide to explore a simulation of the molecular world.

Looking through the brochure, you read many tedious facts about the simulation: how accurate it is in describing sizes, forces, motions, and the like; how similar it is to working tools used by both engineering students and professionals; how you can buy one for your very own home, and so forth. It explains how you can tour the human body, see state-of-the-art nanotechnology in action, climb a bacterium, etc. For starters, you decide to take an introductory tour: simulations of real twentieth-century objects alongside quaint twentieth-century concepts of nanotechnology.

After paying a small fee and memorizing a few key phrases (any variation of "Get me out of here!" will do the most important job), you pull on a powersuit, pocket a Talking Tourguide, step into the simulation chamber, and strap the video goggles over your eyes. Looking through the goggles, you seem to be in a room with a table you know isn't really there and walls that seem too far away to fit in the simulation chamber. But trickery with a treadmill floor makes the walk to the walls seem far enough, and when you walk back and thump the table, it feels solid because the powersuit stops your hand sharply at just the right place. You can even feel the texture of the carvings on the table leg, because the suit's gloves press against your fingertips in the right patterns as you move. The simulation isn't perfect, but it's easy to ignore the defects. On the table is (or seems to be) an old 1990s silicon computer chip. When you pick it up, as the beginners' instructions suggest, it looks like Figure 1A. Then you say, "Shrink me!", and the world seems to expand.

FIGURE 1: POWER OF TEN

Frame (A) shows a hand holding a computer chip. This is shown magnified 100 times in (B). Another factor of 100 magnification (C) shows a living cell placed on the chip to show scale. Yet another factor of 100 magnification (D) shows two nanocomputers beside the cell. The smaller (shown as block) has roughly the same power as the chip seen in the first view; the larger (with only the corner visible) is as powerful as mid-1980s mainframe computer. Another factor of 100 magnification (E) shows an irregular protein from the cell on the lower right, and a cylindrical gear made by molecular manufacturing at top left. Taking a smaller factor of 10 jump, (F) shows two atoms in the protein, with electron clouds represented by stippling. A final factor of 100 magnification (G) reveals the nucleus of the atom as a tiny speck.

Vision and Motion

You feel as though you're falling toward the chip's surface, shrinking rapidly. In a moment, it looks roughly like Figure 1B, with your thumb still there holding it. The world grows blurrier, then everything seems to go wrong as you approach the molecular level. First, your vision blurs to uselessness—there is light, but it becomes a featureless fog. Your skin is tickled by small impacts, then battered by what feel like hard-thrown marbles. Your arms and legs feel as though they are caught in turbulence, pulling to and fro, harder and harder. The ground hits your feet, you stumble and stick to the ground like a fly on flypaper, battered so hard that it almost hurts. You asked for realism, and only the built-in safety limits in the suit keep the simulated thermal motions of air molecules and of your own arms from beating you senseless.

"Stop!" gives you a rest from the suit's yanking and thumping, and "Standard settings!" makes the world around you become more reasonable. The simulation changes, introducing the standard cheats. Your simulated eyes are now smaller than a light wave, making focus impossible, but the goggles snap your vision into sharpness and show the atoms around you as small spheres. (Real nanomachines are as blind as you were a moment ago, and can't cheat.) You are on the surface of the 1990s computer chip, between a cell and two blocky nanocomputers like the ones in Figure 1D. Your simulated body is 50 nanometers tall, about 1/40,000,000 your real size, and the smaller nanocomputer is twice your height. At that size, you can "see" atoms and molecules, as in Figure 1E.

The simulation keeps bombarding you with air molecules, but the standard settings leave out the sensation of being pelted with marbles. A moment ago you were stuck tight to the ground by molecular stickiness, but the standard settings give your muscles the effective strength of steel—at least in simulation—by making everything around you much softer and weaker. The tourguide says that the only unreal features of the simulation have to do with you—not just your ability to see and to ignore thermal shaking and bombardment, but also your sheer existence at a size too small for anything so complex as a human being. It also explains why you can see things move, something about slowing down everything around you by a factor of 10 for every factor of 10 enlargement, and by another factor to allow for your being made stronger and hence faster. And so, with your greater strength and some adjustments to make your arms, legs, and torso less sticky, you can stand, see, feel, and take stock of the situation.

Molecular Texture

The ground underfoot, like everything around you, is pebbly with atom-sized bumps the size of your fingertips. Objects look like bunches of transparent grapes or fused marbles in a variety of pretty but imaginary colors. The simulation displays a view of atoms and molecules much like those used by chemists in the 1980s, but with a sharper 3-D image and a better way to move them and to feel the forces they exert. Actually, the whole simulation setup is nothing but an improved version of systems built in the late 1980s—the computer is faster, but it is calculating the same things. The video goggles are better and the whole-body powersuit is a major change, but even in the 1980s there were 3-D displays for molecules and crude devices that gave a sense of touching them.

The gloves on this suit give the sensation of touching whatever the computer simulates. When you run a fingertip over the side of the smaller nanocomputer, it feels odd, hard to describe. It is as if the surface were magnetic—it pulls on your fingertip if you move close enough. But the result isn't a sharp click of contact, because the surface isn't hard like a magnet, but strangely soft. Touching the surface is like touching a film of fog that grades smoothly into foam rubber, then hard rubber, then steel, all within the thickness of a sheet of corrugated cardboard. Moving sideways, your fingertip feels no texture, no friction, just smooth bumps more slippery than oil, and a tendency to get pulled into hollows. Pulling free of the surface takes a firm tug. The simulation makes your atom-sized fingertips feel the same forces that an atom would. It is strange how slippery the surface is—and it can't have been lubricated, since even a single oil molecule would be a lump the size of your thumb. This slipperiness makes it obvious how nano-scale bearings can work, how the parts of molecular machines can slide smoothly.

But on top of this, there is a tingling feeling in your fingers, like the sensation of touching a working loudspeaker. When you put your ear against the wall of the nanocomputer, you flinch back: for a moment, you heard a sound like the hiss of a twentieth—century television tuned to a channel with no broadcast, with nothing but snow and static—but loud, painfully loud. All the atoms in the surface are vibrating at high frequencies, too fast to see. This is thermal vibration, and it's obvious why it's also called thermal noise.

Gas and Liquid

Individual molecules still move too quickly to see. So, to add one more cheat to the simulation, you issue the command "Whoa!", and everything around seems to slow down by a factor of ten.

On the surface, you now can see thermal vibrations that had been too quick to follow. All around, air molecules become easier to watch. They whiz about as thick as raindrops in a storm, but they are the size of marbles and bounce in all directions. They're also sticky in a magnet-like way, and some are skidding around on the wall of the nanocomputer. When you grab one, it slips away. Most are like two fused spheres, but you spot one that is perfectly round—it is an argon atom, and these are fairly rare. With a firm grip on all sides to keep it from shooting away like a watermelon seed, you pinch it between your steel-strong fingers. It compresses by about 10 percent before the resistance is more than you can overcome. It springs back perfectly and instantly when you relax, then bounces free of your grip. Atoms have an unfamiliar perfection about them, resilient and unchanging, and they surround you in thick swarms.

At the base of the wall is a churning blob that can only be a droplet of water. Scooping up a handful for a closer look yields a swarm of molecules, hundreds, all tumbling and bumbling over one another, but clinging in a coherent mass. As you watch, though, one breaks free of the liquid and flies off into the freer chaos of the surrounding air: the water is evaporating. Some slide up your arm and lodge in the armpit, but eventually skitter away. Getting rid of all the water molecules takes too much scraping, so you command "Clean me!" to dry off.

Too Small and Too Large

Beside you, the smaller nanocomputer is a block twice your height, but it's easy to climb up onto it as the tourguide suggests. Gravity is less important on a small scale: even a fly can defy gravity to walk on a ceiling, and an ant can lift what would be a truck to us. At a simulated size of fifty nanometers, gravity counts for nothing. Materials keep their strength, and are just as hard to bend or break, but the weight of an object becomes negligible. Even without the strength-enhancement that lets you overcome molecular stickiness, you could lift an object with 40 million times your mass—like a person of normal size lifting a box containing a half-dozen fully loaded oil tankers. To simulate this weak gravity, the powersuit cradles your body's weight, making you feel as if you were floating. This is almost like a vacation in an orbital theme park, walking with stickyboots on walls, ceilings, and whatnot, but with no need for anti-nausea medication.

On top of the nanocomputer is a stray protein molecule, like the one in Figure 1E. This looks like a cluster of grapes and is about the same size. It even feels a bit like a bunch of grapes, soft and loose. The parts don't fly free like a gas or tumble and wander like a liquid, but they do quiver like gelatin and sometimes flop or twist. It is solid enough, but the folded structure is not as strong as your steel fingers. In the 1990s, people began to build molecular machinery out of proteins, copying biology. It worked, but it's easy to see why they moved on to better materials.

From a simulated pocket, you pull out a simulated magnifying glass and look at the simulated protein. This shows a pair of bonded atoms on the surface at 10 times magnification, looking like Figure 1F. The atoms are almost transparent, but even a close look doesn't reveal a nucleus inside, because it's too small to see. It would take 1,000 times magnification to be able to see it, even with the head start of being able to see atoms with your naked eye. How could people ever confuse big, plump atoms with tiny specks like nuclei? Remembering how your steel-strong fingers couldn't press more than a fraction of the way toward the nucleus of an argon atom from the air, it's clear why nuclear fusion is so difficult. In fact, the tourguide said that it would take a real-world projectile over a hundred times faster than a high-powered rifle bullet to penetrate into the atomic core and let two nuclei fuse. Try as you might, there just isn't anything you could find in the molecular world that could reach into the middle of an atom to meddle with its nucleus. You can't touch it and you can't see it, so you stop squinting though the magnifying glass. Nuclei just aren't of much interest in nanotechnology.

Puzzle Chains

Taking the advice of the tourguide, you grab two molecular knobs on the protein and pull. It resists for a moment, but then a loop comes free, letting other loops flop around more, and the whole structure seems to melt into a writhing coil. After a bit of pulling and wrestling, the protein's structure becomes obvious: It is a long chain—longer than you are tall, if you could get it straight—and each segment of the chain has one of several kinds of knobs sticking off to the side. With the multicolored, glassy-bead portrayal of atoms, the protein chain resembles a flamboyant necklace. This may be decorative, but how does it all go back together? The chain flops and twists and thrashes, and you pull and push and twist, but the original tight, solid packing is lost. There are more ways to go wrong in folding up the chain than there are in solving Rubik's Cube, and now that the folded structure is gone, it isn't even clear what the result should look like. How did those twentieth-century researchers ever solve the notorious "protein folding problem"? It's a matter of record that they started building protein objects in the late 1980s.

This protein molecule won't go back together, so you try to break it. A firm grip and a powerful yank straightens a section a bit, but the chain holds together and snaps back. Though unfolding it was easy, even muscles with the strength of steel—the strength of Superman—can't break the chain itself. Chemical bonds are amazingly strong, so it's time to cheat again. When you say, "Flimsy world—one second!" while pulling, your hands easily move apart, splitting the chain in two before its strength returns to normal. You've forced a chemical change, but there must be easier ways since chemists do their work without tiny superhands. While you compare the broken ends, they thrash around and bump together. The third time this happens, the chain rejoins, as strong as before. This is like having snap-together parts, but the snaps are far stronger than welded steel. Modern assembler chemistry usually uses other approaches, but seeing this happen makes the idea of molecular assembly more understandable: Put the right pieces together in the right positions, and they snap together to make a bigger structure.

Remembering the "Whoa!" command, you decide to go back to the properly scaled speed for your size and strength. Saying "Standard settings!," you see the thrashing of the protein chain speed up to hard-to-follow blur.

Nanomachines

At your feet is a ribbed, ringed cylindrical object about the size of a soup can—not a messy, loosely folded strand like the protein (before it fell apart), but a solid piece of modern nanotechnology. It's a gear like the one in Figure 1E. Picking it up, you can immediately feel how different it is from a protein. In the gear, everything is held in place by bonds as strong as those that strung together the beads of the protein chain. It can't unfold, and you'd have to cheat again to break its perfect symmetry. Like those in the wall of the nanocomputer, its solidly attached atoms vibrate only slightly. There's another gear nearby, so you fit them together and make the atomic teeth mesh, with bumps on one fitting into hollows on the other. They stick together, and the soft, slick atomic surfaces let them roll smoothly.

Underfoot is the nanocomputer itself, a huge mechanism built in the same rigid style. Climbing down from it, you can see through the transparent layers of the wall to watch the inner works. An electric motor an arm-span wide spins inside, turning a crank that drives a set of oscillating rods, which in turn drive smaller rods. This doesn't look like a computer; it looks more like an engineer's fantasy from the nineteenth century. But then, it is an antique design–the tourguide said that the original proposal was a piece of exploratory engineering dating from the mid-1980s, a mechanical design that was superseded by improved electronic designs before anyone had the tools to build even a prototype. This simulation is based on a version built by a hobbyist many years later.

The mechanical nanocomputer may be crude, but it does work, and it's a lot smaller and more efficient than the electronic computers of the early 1990s. It's even somewhat faster. The rods slide back and forth in a blur of motion, blocking and unblocking each other in changing patterns, weaving patterns of logic. This nanocomputer is a stripped-down model with almost no memory, useless by itself. Looking beyond it, you see the other block—the one on the left in Figure 1D—which contains a machine powerful enough to compete with most computers built in 1990. This computer is a millionth of a meter on a side, but from where you stand, it looks like a blocky building looming over ten stories tall. The tourguide says that it contains over 100 billion atoms and stores as much data as a room full of books. You can see some of the storage system inside: row upon row of racks containing spools of molecular tape somewhat like the protein chain, but with simple bumps representing the 1s and 0s of computer data.

These nanocomputers seem big and crude, but the ground you're now standing on is also a computer—a single chip from 1990, roughly as powerful as the smaller, stripped-down nanocomputer at your side. As you gaze out over the chip, you get a better sense for just how crude things were a few decades ago. At your feet, on the smallest scale, the chip is an irregular mess. Although the wall of the nanocomputer is pebbly with atomic-scale bumps, the bumps are as regular as tile. The chip's surface, though, is a jumble of lumps and mounds. This pattern spreads for dozens of paces in all directions, ending in an irregular cliff marking the edge of a single transistor. Beyond, you can see other ridges and plateaus stretching off to the horizon. These form grand, regular patterns, the circuits of the computer. The horizon—the edge of the chip—is so distant that walking there from the center would (as the tourguide warns) take days. And these vast pieces of landscaping were considered twentieth-century miracles of miniaturization?

Cells and Bodies

Even back then, research in molecular biology had revealed the existence of smaller, more perfect machines such as the protein molecules in cells. A simulated human cell–put here because earlier visitors wanted to see the size comparisons—its on the chip next to the smaller nanocomputer. The tourguide points out that the simulation cheats a bit at this point, making the cell act as though it were in a watery environment instead of air. The cell dwarfs the nanocomputer, sprawling across the chip surface and rearing into the sky like a small mountain. Walking the nature trail around its edge would lead across many transistor-plateaus and take about an hour. A glance is enough to show how different it is from a nanocomputer or a gear: it looks organic, it bulges and curves like a blob of liver, but its surface is shaggy with waving molecular chains.

Walking up to its edge, you can see that the membrane wrapping the cell is fluid (cell walls are for stiff things like plants), and the membrane molecules are in constant motion. On an impulse, you thrust your arm through the membrane and poke around inside. You can feel many proteins bumping and tumbling around in the cell's interior fluid, and a crisscrossing network of protein cables and beams. Somewhere inside are the molecular machines that made all these proteins, but such bits of machinery are embedded in a roiling, organic mass. When you pull your arm out, the membrane flows closed behind. The fluid, dynamic structure of the cell is largely self healing. That's what let scientists perform experimental surgery on cells with the old, crude tools of the twentieth century: They didn't need to stitch up the holes they made when they poked around inside.

Even a single human cell is huge and complex. No real thinking being could be as small as you are in the simulation: A simple computer without any memory is twice your height, and the larger nanocomputer, the size of an apartment complex, is no smarter than one of the submoronic computers of 1990.

Not even a bendable finger could be as small as your simulated fingers: in the simulation, your fingers are only one atom wide, leaving no room for the slimmest possible tendon, to say nothing of nerves.

For a last look at the organic world, you gaze out past the horizon and see the image of your own, full-sized thumb holding the chip on which you stand. The bulge of your thumb rises ten times higher than Mount Everest. Above, filling the sky, is a face looming like the Earth seen from orbit, gazing down. It is your own face, with cheeks the size of continents. The eyes are motionless. Thinking of the tourguide's data, you remember: the simulation uses the standard mechanical scaling rules, so being 40 million times smaller has made you 40 million times faster. To let you pull free of surfaces, it increased your strength by more than a factor of 100, which increased your speed by more than a factor of 10. So one second in the ordinary world corresponds to over 400 million here in the simulation. It would take years to see that huge face in the sky complete a single eyeblink.

The coming technological revolution

It seems like magic. A small appliance, about the size of a washing machine, that is able to manufacture almost anything. It is called a nanofactory. Fed with simple chemical stocks, this amazing machine breaks down molecules, and then reassembles them into any product you ask for. Packed with nanotechnology and robotics, weighing 200 pounds and standing half as tall as a person, it can produce two tons per day of products. Control is simple: a touch screen selects the type and number of products to produce. It costs very little to operate, just the price of materials fed into it. In one hour, $20 worth of chemicals can be converted into 100 pairs of shoes, or 50 shovels, or 200 cell phones, or even a duplicate nanofactory!

Impossible? Today, maybe, but not tomorrow. The technology to create such a machine is speedily being developed. A nanofactory will be the end result of a convergence between nanotechnology (molecular scale engineering), rapid prototyping, and automated assembly. These are all present-day technologies. None of them has yet reached its full potential, but each of them is advancing rapidly, driven by powerful economic, social, and military forces. The integration of the three technologies will be far more powerful than the sum of the parts.

Some experts claim that a crash program started today could complete the first working nanofactory within a decade at a cost of between five and ten billion dollars. And once the first one is built, it can start making copies of itself. Five to ten billion dollars is a lot of money, of course, and many people will question if it could not be better spent on something else. But imagine the economic, environmental and humanitarian benefits, when nearly any product can be manufactured on the spot for about $1 per pound. No more shipping costs or time spent waiting. No more wasted resources or hazardous byproducts. No more starvation, homelessness, or poverty.

Already scientists have made chemical reactions happen by directly manipulating the individual atoms. They can draw lines of chemicals only ten atoms wide. They can send electricity down molecular wires. They can attach propellers to molecular motors and analyze their performance. They can make functioning tweezers from DNA molecules. Within a few years, we will have the ability to build three-dimensional, active, molecular constructions. It's a small and predictable step to building robots and chemical plants at the nanometer scale.

It sounds too good to be true: a non-polluting, personal-size machine that within a few hours and for a few dollars can manufacture almost anything—clothing, books, tools, communication devices—but there is a catch. It can also manufacture weapons, poisons, tiny surveillance cameras, and other illicit products. How will this be controlled?

Imagine the possibilities! And the problems...

What we're doing about it

The mission of the Center for Responsible Nanotechnology (a non-profit program of World Care) is to raise awareness of the issues presented by molecular nanotechnology: the benefits and dangers, and the possibilities for responsible use.

Designing and developing molecular nanotechnology (MNT) is a major challenge in itself. It will not be easy, and it will not happen overnight. But it will happen, and it should happen. A greater challenge—and one that has not been addressed—is creating the infrastructure to administer the most powerful technology imaginable in a way that allows its safe and effective use, but that protects investors, users, and innocent bystanders.

"Nanotechnology will give rise to a host of novel social, ethical, philosophical and legal issues. It will be important to have a group in place to predict and work to alleviate anticipated problems."

— US Rep. Mike Honda (D-Cal.)

The technology is already on its way. But who will control it? If MNT is not administered properly, there is great risk of it being used badly—either by the entity that first develops it, or by groups that later gain access to it. Development or control of the technology by a special interest group would probably lead to military or economic oppression. Two competing programs could lead to an unstable arms race. Uncontrolled release would make the full power of the technology available to terrorists, criminals, dictators, and irresponsible users. The safest course appears to be a single, rapid, worldwide development program by an organization that recognizes the necessity of wise administration.

Christine Peterson of the Foresight Nanotech Institute made this point in her April 2003 testimony to the US House Committee on Science:

"In developing a powerful technology, delay may seem to add safety, but the opposite could be the case for molecular manufacturing. A targeted R&D project today aimed at this goal would need to be large and, therefore, visible and relatively easy to monitor. As time passes, the nanoscale infrastructure improves worldwide, enabling faster development everywhere, including places that are hard to monitor. The safest course may be to create a fast-moving, well-funded, highly-focused project located where it can be closely watched by all interested parties. Estimates are that such a project could reach its goal in 10-15 years."

CRN is dedicated to studying the problem of how to make MNT as safe as possible. We will find technological solutions and plan systems of administration. We will work to educate people at all levels about the dangers of nanotechnology, and the possible solutions to those dangers.

Beyond addressing measures of safety and environmental protection, we believe that responsible use of MNT should include consideration for ways to reduce the gap between the haves and the have-nots. This new technology can make a tremendous impact for good; unwise regulation might impede such hopes. As suggested in the Foresight Guidelines: "Experimenters and industry should have the maximum safe opportunities to develop and commercialize the molecular manufacturing industry. In addition, MNT should be developed in ways that make it possible to distribute the benefits of the technology to the four-fifths of humanity currently desperate to achieve material wealth at any environmental or security cost."

Effective administration will not be easy, and it is unlikely that a wise course of action can evolve without guidance. There are too many risks to avoid, too many benefits to preserve, and too many special interests to satisfy. A technology this powerful has implications in the areas of national security, commercial rights, human rights, global environment, and even cultural stability. Any single organization with a narrow focus will create too many regulations while trying to control things that it does not know how to control; too many regulations will create an unregulated black market, which creates unacceptable risks. We believe that MNT must be regulated at a global level, but the regulatory system must be designed with extreme care to be acceptable to the world's population—and to avoid the internal corruption that naturally accompanies so much power. The design of such a system is one of our main concerns.

Simple, non-factory forms of nanotechnology already are being developed, and already are raising safety questions. Although these simple forms are less dangerous—and less useful—than the advanced nanotechnology that is our main concern, we will be addressing today's issues of safety as well as tomorrow's.

The purpose of CRN is to investigate the wise use of molecular nanotechnology, and to educate those who will influence its use, or be affected by it. Through this we hope to see our vision made real: a world in which MNT is widely used for productive and beneficial purposes, and where malicious uses are limited by effective administration of the technology.

Four Generations of Nano Technology

Mihail (Mike) Roco of the U.S. National Nanotechnology Initiative has described four generations of nanotechnology development (see chart below). The current era, as Roco depicts it, is that of passive nanostructures, materials designed to perform one task. The second phase, which we are just entering, introduces active nanostructures for multitasking; for example, actuators, drug delivery devices, and sensors. The third generation is expected to begin emerging around 2010 and will feature nanosystems with thousands of interacting components. A few years after that, the first integrated nanosystems, functioning (according to Roco) much like a mammalian cell with hierarchical systems within systems, are expected to be developed.

Some experts may still insist that nanotechnology can refer to measurement or visualization at the scale of 1-100 nanometers, but a consensus seems to be forming around the idea (put forward by the NNI's Mike Roco) that control and restructuring of matter at the nanoscale is a necessary element. CRN's definition is a bit more precise than that, but as work progresses through the four generations of nanotechnology leading up to molecular nanosystems, which will include molecular manufacturing, we think it will become increasingly obvious that "engineering of functional systems at the molecular scale" is what nanotech is really all about.

Conflicting Definitions

Unfortunately, conflicting definitions of nanotechnology and blurry distinctions between significantly different fields have complicated the effort to understand the differences and develop sensible, effective policy.

The risks of today's nanoscale technologies (nanoparticle toxicity, etc.) cannot be treated the same as the risks of longer-term molecular manufacturing (economic disruption, unstable arms race, etc.). It is a mistake to put them together in one basket for policy consideration—each is important to address, but they offer different problems and will require different solutions. As used today, the term nanotechnology usually refers to a broad collection of mostly disconnected fields. Essentially, anything sufficiently small and interesting can be called nanotechnology. Much of it is harmless. For the rest, much of the harm is of familiar and limited quality. But as we will see, molecular manufacturing will bring unfamiliar risks and new classes of problems.

General-Purpose Technology

Nanotechnology is sometimes referred to as a general-purpose technology. That's because in its advanced form it will have significant impact on almost all industries and all areas of society. It will offer better built, longer lasting, cleaner, safer, and smarter products for the home, for communications, for medicine, for transportation, for agriculture, and for industry in general.

Imagine a medical device that travels through the human body to seek out and destroy small clusters of cancerous cells before they can spread. Or a box no larger than a sugar cube that contains the entire contents of the Library of Congress. Or materials much lighter than steel that possess ten times as much strength. — U.S. National Science Foundation

Dual-Use Technology

Like electricity or computers before it, nanotech will offer greatly improved efficiency in almost every facet of life. But as a general-purpose technology, it will be dual-use, meaning it will have many commercial uses and it also will have many military uses—making far more powerful weapons and tools of surveillance. Thus it represents not only wonderful benefits for humanity, but also grave risks.

A key understanding of nanotechnology is that it offers not just better products, but a vastly improved manufacturing process. A computer can make copies of data files—essentially as many copies as you want at little or no cost. It may be only a matter of time until the building of products becomes as cheap as the copying of files. That's the real meaning of nanotechnology, and why it is sometimes seen as "the next industrial revolution."

My own judgment is that the nanotechnology revolution has the potential to change America on a scale equal to, if not greater than, the computer revolution. — U.S. Senator Ron Wyden (D-Ore.)

The power of nanotechnology can be encapsulated in an apparently simple device called a personal nanofactory that may sit on your countertop or desktop. Packed with miniature chemical processors, computing, and robotics, it will produce a wide-range of items quickly, cleanly, and inexpensively, building products directly from blueprints.

Exponential Proliferation

Nanotechnology not only will allow making many high-quality products at very low cost, but it will allow making new nanofactories at the same low cost and at the same rapid speed. This unique (outside of biology, that is) ability to reproduce its own means of production is why nanotech is said to be an exponential technology. It represents a manufacturing system that will be able to make more manufacturing systems—factories that can build factories—rapidly, cheaply, and cleanly. The means of production will be able to reproduce exponentially, so in just a few weeks a few nanofactories conceivably could become billions. It is a revolutionary, transformative, powerful, and potentially very dangerous—or beneficial—technology.

How soon will all this come about? Conservative estimates usually say 20 to 30 years from now, or even much later than that. However, CRN is concerned that it may occur sooner, quite possibly within the next decade. This is because of the rapid progress being made in enabling technologies, such as optics, nanolithography, mechanochemistry and 3D prototyping. If it does arrive that soon, we may not be adequately prepared, and the consequences could be severe.

What is Nanotechnology?

A Basic definition:

Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.

In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.

The Meaning of Nanotechnology

When K. Eric Drexler (right) popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.

Much of the work being done today that carries the name 'nanotechnology' is not nanotechnology in the original meaning of the word. Nanotechnology, in its traditional sense, means building things from the bottom up, with atomic precision. This theoretical capability was envisioned as early as 1959 by the renowned physicist Richard Feynman.

I want to build a billion tiny factories, models of each other, which are manufacturing simultaneously. . . The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. — Richard Feynman, Nobel Prize winner in physics

Based on Feynman's vision of miniature factories using nanomachines to build complex products, advanced nanotechnology (sometimes referred to as molecular manufacturing) will make use of positionally-controlled mechanochemistry guided by molecular machine systems. Formulating a roadmap for development of this kind of nanotechnology is now an objective of a broadly based technology roadmap project led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Nanotech Institute.

Shortly after this envisioned molecular machinery is created, it will result in a manufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications.

What is nanotechnology all about?

Nanotechnology is the engineering of tiny machines — the projected ability to build things from the bottom up inside personal nanofactories (PNs), using techniques and tools being developed today to make complete, highly advanced products. Ultimately, nanotechnology will enable control of matter at the nanometer scale, using mechanochemistry. Shortly after this envisioned molecular machinery is created, it will result in a manufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications.

A nanometer is one billionth of a meter, roughly the width of three or four atoms. The average human hair is about 25,000 nanometers wide.

You can see a longer explanation here. And to check out more of those tiny machines, click here.

What's a personal nano factory?

It's a proposed new appliance, something that might sit on a countertop in your home. To build a personal nanofactory (PN), you need to start with a working fabricator, a nanoscale device that can combine individual molecules into useful shapes. A fabricator could build a very small nanofactory, which then could build another one twice as big, and so on. Within a period of weeks, you have a tabletop model.

Products made by a PN will be assembled from nanoblocks, which will be fabricated within the nanofactory. Computer aided design (CAD) programs will make it possible to create state-of-the-art products simply by specifying a pattern of predesigned nanoblocks. The question of when we will see a flood of nano-built products boils down to the question of how quickly the first fabricator can be designed and built.

MOVIE TIME: A short film called Productive Nanosystems: from Molecules to Superproducts depicts an animated view of a nanofactory and demonstrates key steps in the sample process that converts basic molecules into a billion-CPU laptop computer. The 4-minute streaming video is online here.

What could nano factories produce?

bullet Lifesaving medical robots or untraceable weapons of mass destruction.

bullet Networked computers for everyone in the world or networked cameras so governments can watch our every move.

bullet Trillions of dollars of abundance or a vicious scramble to own everything.

bullet Rapid invention of wondrous products or weapons development fast enough to destabilize any arms race.

How does 'mechanochemistry' work?

It's a bit like enzymes (if you know your chemistry): you fix onto a molecule or two, then twist or pull or push in a precise way until a chemical reaction happens right where you want it. This happens in a vacuum, so you don't have water molecules bumping around. It's a lot more controllable that way.

So, if you want to add an atom to a surface, you start with that atom bound to a molecule called a "tool tip" at the end of a mechanical manipulator. You move the atom to the point where you want it to end up. You move the atom next to the surface, and make sure that it has a weaker bond to the tool tip than to the surface. When you bring them close enough, the bond will transfer. This is ordinary chemistry: an atom moving from one molecule to another when they come close enough to each other, and when the movement is energetically favorable. What's different about mechanochemistry is that the tool tip molecule can be positioned by direct computer control, so you can do this one reaction at a wide variety of sites on the surface. Just a few reactions give you a lot of flexibility in what you make.

Why do some scientists dismiss this stuff as science fiction?

The whole concept of advanced nanotechnology — molecular manufacturing (MM) — is so complex and unfamiliar, and so staggering in its implications, that a few scientists, engineers, and other pundits have flatly declared it to be impossible. The debate is further confused by science-fictional hype and media misconceptions.

It should be noted that none of those who dismiss MM are experts in the field. They may work in chemistry, biotechnology, or other nanoscale sciences or technologies, but are not sufficiently familiar with MM theory to critique it meaningfully.

Many of the objections, including those of the late Richard Smalley, do not address the actual published proposals for MM. The rest are unfounded and incorrect assertions, contradicted by detailed calculations based on the relevant physical laws.

Is nanotechnology bad or good?

Nanotechnology offers great potential for benefit to humankind, and also brings severe dangers. While it is appropriate to examine carefully the risks and possible toxicity of nanoparticles and other products of nanoscale technology, the greatest hazards are posed by malicious or unwise use of molecular manufacturing. CRN's focus is on designing and promoting mechanisms for safe development and effective administration of MM.

If MM is so dangerous, why not just completely ban all research and development?

Viewed with pessimism, molecular manufacturing could appear far too risky to be allowed to develop to anywhere near its full potential. However, a naive approach to limiting R&D, such as relinquishment, is flawed for at least two reasons. First, it will almost certainly be impossible to prevent the development of MM somewhere in the world. China, Japan, and other Asian nations have thriving nanotechnology programs, and the rapid advance of enabling technologies such as biotechnology, MEMS, and scanning-probe microscopy ensures that R&D efforts will be far easier in the near future than they are today. Second, MM will provide benefits that are simply too good to pass up, including environmental repair; clean, cheap, and efficient manufacturing; medical breakthroughs; immensely powerful computers; and easier access to space.

What about "grey goo"?

The dangers of self-replicating nanobots — the so-called grey goo — have been widely discussed, and it is generally perceived that molecular manufacturing is uncomfortably close to grey goo. However, the proposed production system that CRN supports does not involve free-floating assemblers or nanobots, but much larger factories with all the nanoscale machinery fastened down and inert without external control. As far as we know, a self-replicating mechanochemical nanobot is not excluded by the laws of physics, but such a thing would be extremely difficult to design and build even with a full molecular manufacturing capability. Fiction like Michael Crichton's Prey might be good entertainment, but it's not very good science.

How soon will molecular manufacturing be developed?

Based on our studies, CRN believes that molecular manufacturing could be successfully developed within the next ten years, and almost certainly will be developed within twenty years. For more, see our Timeline page.

Shouldn't we be working on current problems like poverty, pollution, and stopping terrorism, instead of putting money into these far future technologies?

We should do both! Development and application of molecular manufacturing clearly can have a positive impact on solving many of today's most urgent problems. But it's equally clear than MM can exacerbate many of society's ills. Knowing that it may be developed within the next decade or two (which is not "far future"), makes preparation for MM an urgent priority.