Cusp of a Revolution

Exponential manufacturing refers to a manufacturing system that can be used to fabricate additional copies of itself. There has been at least one exponential manufacturing system in the past – blacksmithing – but its impact was limited. Subsequently, the benefits of automation and standardization led to special-purpose machines and factories.

As technologies for fabrication and automation become increasingly portable, flexible, lightweight and precise, it seems likely that general purpose exponential manufacturing will regain its appeal. With precision and intricacy coming from computers rather than skilled labor, and with far faster doubling times, exponential manufacturing may have more potential impact than did blacksmithing - which named the Iron Age.

Rapid prototyping (RP) systems are not yet capable of exponential manufacturing, and RP has to date been struggling out of the shadow of traditional manufacturing. This has kept RP systems scarce and expensive. But when this changes, it could do so in a hurry. And today's capabilities define a lower bound, not an upper bound, for the performance of products (including the manufacturing systems themselves). In fact, detailed and sober attempts to calculate how far the capabilities could extend have produced figure of merit several orders of magnitude higher than today's.

In short, exponential manufacturing is poised to overtake traditional manufacturing, including traditionally manufactured RP systems - and may do so very rapidly. Any stakeholder in the manufacturing of products (including designers and consumers) would do well to study the possibilities and implications in advance.

Past

Several centuries ago, a blacksmith's shop was a general-purpose manufacturing center. Cold iron hitting hot iron could be used to cut, punch, bend, shape and weld the iron, and even change its material properties to some degree. And, of course, the techniques could be used to make more cold-iron tools.

A skilled blacksmith could have probably duplicated his stock of tools in a few months - but the skills took years to learn, and the learning process required attention from existing blacksmiths. The scarcity of iron and fuel, as well as the limited market caused by necessarily high prices, combined with the scarcity of blacksmiths limited the speed with which blacksmithing could grow and the economic impact it could have.

Although blacksmithing was a general-purpose technology, and in theory, an exponential technology, its high cost and consumption of scarce skills limited it to being only a part of a much larger manufacturing infrastructure, which also used other materials such as wood and stone.

As automation and engines birthed the Industrial Revolution and improved transportation, blacksmithing slowly gave way to centralized manufacturing. The advantages of standardization and the availability of new alloys and metals that couldn't be forge-worked contributed to the shift. The closest modern equivalent of a blacksmith's shop may be a tool-and-die shop - but the tools and dies are costly due to the skilled labor required, and rather than being consumer products, they usually go into machines that make products inexpensively.

Present

RepRap, which is short for Replicating Rapid-prototyper, is a project which aims to create a practical self-copying fused deposition modeling (FDM) system. It is a three-axis system capable of depositing molten plastic to form 3D structural parts; metal and ceramic materials are planned for subsequent versions. By building its own plastic parts - and eventually, its own circuit boards - the RepRap machine aims to develop an inexpensive desktop system accessible to hobbyists (see Time-Compression Technologies' TCT Focus, Adrian Bowyer - the founder and leader of the RepRap project - in the May/June 2006 issue).

A few months ago the system built the first working component for itself. The intention is that any part not buildable by the system (such as motors, steel rods and microcontrollers) should be available widely and inexpensively. The system should be capable of being assembled by hobby-grade skills such as soldering. Its purchased components plus feedstock are projected to cost less than $400. The project Web site currently states that they hope to announce self-replication in 2008.

RepRap machines are intended to spread widely and rapidly among the hobbyist community. The design will be made available for free, and improvements will be encouraged. The parts for the entire system are projected to cost only a few hundred dollars. As long as demand exists, the number of systems might double every week or so, based on fabrication and assembly time. It will be interesting to see whether the system, with subsequent improvements, manages to "cross the chasm" from hobbyists to commercial applications.

RepRap highlights one of several advantages inherent in building things smaller. Small machines, in general, work faster than larger ones. Where a machine shop or a blacksmith's shop might require months to produce its own mass and complexity of product, RepRap could do it in weeks. For comparison, a cheap inkjet printer can print its weight in ink in about a day.

Faster operation is not the only reason RepRap may have rapid impact. Thanks to computer-driven automation, the skill and training required to build and use a RepRap machine will be minimal compared with blacksmithing or tool-and-die making.

RepRap is not the only homebuilt RP project. Fab@Home has developed a somewhat more expensive syringe-deposition machine made from cut plastic sheets-still significantly cheaper than even low-end commercial RP systems. Fab@Home is not intended to build its own components, but it shows that RepRap is not an isolated case.

Future

For several reasons, exponential manufacturing may be more effective at smaller device sizes. Tabletop devices are interestingly powerful; projection to molecular scale indicates very high potential for manufacturing systems and products. It would be a mistake to judge nanoscale manufacturing by the problems that have limited MEMS; there are other manufacturing methods that do not have the limitations of lithography.

Molecular manufacturing, a subfield of nanotechnology, provides an indication of where this might lead. Molecular manufacturing is the use of programmable chemistry to build exponential manufacturing systems and high-performance products. In a molecular manufacturing system, sub-micron machines would perform individual molecular synthesis operations at blinding speed. It appears that the machines can be made small enough and fast enough to build their own mass out of individual molecules in a matter f hours.

Over the past several hundred years, several strong trends have developed and seem likely to continue:

• Materials become stronger
• More operations go into each product
• Tools become more complex, with more automated control
• Physical features and tolerances become smaller
• Components become better characterized and standardized
• Computation becomes dramatically cheaper

Currently, theory and calculation for molecular manufacturing have advanced quite a ways beyond laboratory capabilities, and how quickly the lab can catch up remains a matter of controversy. Some observers, including this author, expect some form of exponential molecular manufacturing to be developed within current planning horizons. On the other hand, some nanotechnologists dispute the value of the molecular manufacturing approach - which implies that they may expect another nanotechnology approach to out-compete it. Whether or not they are right, the calculated capabilities of molecular manufacturing are worth studying, because they indicate that future RP and exponential manufacturing technologies may represent vast and highly competitive improvements over anything available today.

Molecular manufacturing benefits from several scaling laws, which imply performance many orders of magnitude greater than today's mechanical or biological systems. In addition, molecular components are inherently precise due to the discrete nature of covalent bonds. This should make automation and maintenance of precision significantly easier, and improve material strength. Precise construction also should minimize wear and friction, essentially eliminating the need for maintenance.

Building at scales vastly smaller than the feature size of any existing manufactured product, the number of potential design choices - thus, the number of products - is unimaginably huge. Molecular manufacturing will be limited by ability to design rather than by materials or components, but the reliability and standardization that comes from building directly with perfectly identical atoms will further aid design.

Further Studies

Exponential manufacturing may be revolutionary and needs to be studied. Many of the studies will be valuable to RP and other manufacturing interests. An exponential manufacturing technology would be able to double itself easily, leading to rapid growth of manufacturing capacity - perhaps to the point of non-scarcity. The economic and security implications of nonscarce general purpose manufacturing (including impacts on other manufacturing technologies) have never been experienced and may not be well understood.

Rapid prototyping is approaching an exponential capability. There will probably be a number of competing and/or cooperating efforts. Studies of exponential manufacturing would benefit everyone who is building RP systems, at least by warning them what to expect.

Exponential manufacturing may develop from technologies outside present-day RP trends. For example, the laboratory of Nadrian Seeman, a professor of chemistry at New York University, has designed and built a machine out of the molecule DNA, which is a programmed by the related molecule RNA, and builds DNA molecules - though it cannot yet built molecules of equivalent complexity to itself. Although it is too early to speculate on the applications of possible future exponential manufacturing technologies based on chemistry, the point is that several different technological pathways may lead to useful exponential manufacturing systems.

A broad spectrum of technologies can be studied by rating the technologies relative to just a few dimensions - starting with the potential impact of their exponential capability. This may provide a broad overview of tech trends to producers of RP and other manufacturing technologies. Each exponential manufacturing system will have its own set of capabilities and limitations. For example:

• How rapidly can it create a duplicate? (doubling time or relative throughput)
• What range of products can it make? How general purpose is it?
• How much does the system cost? How much do its products cost?
• What are the scarce resources that limit its exponential growth?
• When will the technology likely become available?

Once these questions are answered for a given technology, it will be possible to begin technology, it will be possible to begin technology, it will be possible to begin to forecast its effects. For example:

• How competitive is the technology?
• How broad will its impacts be?
• Does the technology pose a weapons proliferation or other security risk?
• To what extent will the technology drive further technological advances?

Several manufacturing technologies have the potential to go exponential. In addition to studying individual technologies, general studies could be undertaken that would be applicable across a continuum or spectrum of technological possibilities. For example:

• What are the economic implications of non-scarce manufacturing equipment?
• In what ways will general purpose rapid prototyping enable product design/product rollout?
• Is there a point beyond which software forms the main limitation to product development?

Established manufacturing and rapid prototyping interests will likely be tempted to try to fight the development of exponential manufacturing by various protectionist policies. Since this would likely be a bad idea, the issues need to be studied. The required technologies of automation, actuation and fabrication are simple enough to be available worldwide. If exponential manufacturing is capable of being a threat to earlier business models, it will be a threat to earlier business models, it will be a threat regardless of whether it is excluded from a region. Exponential manufacturing may best fit areas that are currently less industrialized, leading to a reverse technology gap. For example, raising barriers to exponential manufacturing technologies in the U.S. could eventually put American manufacturing interests in a very uncompetitive position. In this context, it is worth noting that U.S. nanotechnology interests have pursued a campaign of active opposition to molecular manufacturing, which will quite likely result in the development of that technology overseas before it is developed in the U.S.

Conclusion

Exponential manufacturing appears poised to make a significant, possible major, change in manufacturing and economics. Exponential manufacturing is not completely new - with enough time, the present-day manufacturing infrastructure can build more of itself, and in a sense, a blacksmith's shop has been self-duplicating for hundred of years. However, there are two new factors. The first is the combination of exponential manufacturing and automation. For the first time, exponential manufacturing capabilities will required minimal human skill and labor. The second new factor is miniaturization, which leads to faster doubling times due to scaling laws. Technologies currently in advanced stages of prerelease development aim at doubling times a week - far faster than any current manufacturing technology. This implies that products within their design space may benefit from nonscarce manufacturing systems.

Present-day exponential manufacturing systems are just the tip of the iceberg. Studies of molecular manufacturing provide some indication of the potential power of exponential manufacturing systems. Although the designs are well within the limits of physics and materials, benefiting from simple scaling laws and a few of the simpler tricks of nonoscale physics and designed within a narrow fraction of the space of nonoscale phenomena and constructions, molecular manufacturing systems nonetheless promise mechanical capabilities that are astonishingly powerful in comparison with either biological systems or today's machines. Given the cautious and limited character of existing designs for molecular manufacturing systems, molecular manufacturing should not be taken as an upper bound to capability; rather, it should be treated as an intermediate milestone, indicating levels of performance that can reasonably be expected to be achieved as exponential manufacturing is developed. At the same time, the projected extremes of performance (by today's standards) should serve as a spur for early research into the implications of exponential manufacturing.

The RepRap project shows that exponential manufacturing is almost here. Hundreds, perhaps thousands of hobbyists will soon be working to improve their rapid prototyping systems and develop new applications for them. It is too early to predict that this will impact existing rapid prototyping companies as strongly as open-source software has impacted commercial software (providing inspiration and inventions as well as strong competition in some areas); however, it would certainly be imprudent to dismiss these possibilities, especially given the engineering projection of future capabilities.

Any organization interested in rapid prototyping should extend that interest to exponential manufacturing. Several reasons for this should now be clear. Rapid prototyping and exponential manufacturing will use a lot of the same tools, at least in the near term, and will share technological advances. Proliferation of manufacturing systems may lead to the formation of policies to cope with issues such as undesirable products or intellectual property, and these policies will probably overlap with interests of other manufacturing concerns. Exponential manufacturing may come to compete economically with more conventional rapid prototyping and perhaps even with non-RP manufacturing. Understanding how to balance these issues and use the technology and impacts of exponential manufacturing to best advantage will be relevant to an increasingly wide spectrum of manufacturers.

Chris Phoenix lives in South Carolina and has studied nanotechnology for more than 15 years. He obtained his BS in Symbolic Systems and MS in Computer Science from Stanford University in 1991. From 1991 to 1997, he worked as an embedded software engineer at Electronics for Imaging. In 1997, he left the software field to concentrate on dyslexia correction and research. Since 2000, he has focused on studying and writing about molecular manufacturing. In 2002, Chris co-founded the Center for Responsible Nanotechnology (>http://crnano.org/.) where he is the director of Research. Chris is a published author in nanotechnology and nanomedical research, and maintains close contact with many leading researchers in the field. 

Visit >www.reprap.org to learn more about these technologies.

Resources

"Large-Product General-Purpose Design and Manufacturing Using Nanoscale Modules: Final Report," Chris Phoenix and Tihamer Toth-Fejel, CP-04-01, NASA Institute for Advanced Concepts, May 2005.