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The September 2004 nanotechnology special issue of Mechanical Engineering focuses on near-term nanoscale technology research, but seems comfortable with molecular manufacturing as well. Perhaps as a result, their advice about the role of mechanical engineering in nanoscale technology is also good preparation for developing integrated, multiscale nanofactories and their products.
The issue's editor, in a piece titled "Far Out, or Well Grounded?" writes that he's "obsessed with the idea of infinitesimal robots building objects from molecule-size parts." He reflects, "But is that really feasible? No one can honestly say." But he points out that "Work in the nanoscale is grounded in the real world and real problems" and concludes, "Who better to make the nanorobots of my dreams than the folks who already make industrial machines in the here and now?"
The second item of the "Nano Bits" compilation is introduced thus: "The holy grail of nanotechnology is the atomic-scale factory. Computer-controlled nanorobots would assemble molecule-size parts to make all manner of miniature products. A sugar cube-size manufacturing plant is not close to being built, but scientists at Lawrence Berkeley National Laboratory in California have demonstrated one piece of a futuristic factory." The topic is a technique for moving single atoms of metal from one cluster to another along a carbon nanotube.
The advice on connecting mechanical engineering to nanotechnology is found in "Engineering Without Limit".
"One of the most important issues related to nanotechnology is systems integration and packaging. ....how do we integrate these building blocks in a rational manner to make a functional device or a system? This step requires design based on the understanding of nanoscale science, and on new manufacturing techniques. .... Assembling large quantities of nanostructures in a rational and rapid manner requires tooling, imaging systems, instrumentation, sensors, and control systems. After nanostructures are assembled into functional devices, they need to be packaged so that they can interact with their environment and yet retain the nanoness that provides the unique function and performance. These concerns are similar to those found in conventional manufacturing, though there is a call for a level of precision that is not required by macroscale designers." (Emphasis added.)
I'd like to add a useful comment here, but that quote says it better than I could.
I found this paragraph particularly interesting: "[I]t is often difficult to isolate nanoscale phenomena as we do at customary scales. That is, thermal, electronic, mechanical, and chemical effects are often related to each other. By changing one, it is possible to influence the others. This, of course, emphasizes the need for interdisciplinary knowledge."
Thermal and mechanical effects, and conventional electronics and chemistry, are of course statistical. So one implication of this quote is that statistics will have to be replaced with an understanding of the individual behavior of individual components. A deeper implication is that the physics you learned in high school is not the right set of rules for the nanoscale. But that "physics" was essentially just a set of engineering rules. New engineering rules will have to be developed, perhaps forming new disciplines like chemoelectrics and thermomechanics. But there will be rules. And like all engineering rules, most of them will be irrelevant in many if not most cases.
Thermoelectrics, by the way, is already an engineering concept. The article says that mechanical engineers understand the transport of heat and charge better than other technologists, so "will almost certainly devise the solution" to thermoelectric solar cells.
Structures with mechanical motifs may be useful in medicine: "Nanoparticles and nanowires exist on a scale similar to biomolecules such as DNA and proteins. This suggests that the biological sciences can provide crucial insights to the behavior of such material and that nanoscale devices may be used for medical applications."
A bold and very important statement: "Mechanical engineering programs need to ensure that their students are given a solid grounding in the fundamentals of physics, chemistry, and biology." This goes beyond giving lip service to interdisciplinary approaches; the statement was not qualified, and appears to say that all mechanical engineers should be thus trained. It goes on to say that students must be trained to develop new intuitions, and that "Topics such as solid state physics, chemical thermodynamics, surface forces at the atomic and molecular scale, nanofluidics, and motion and behavior of nanoscale structures—most of which receive little if any attention in the traditional undergraduate ME curriculum—will need to be integrated into core courses such as thermodynamics, heat transfer, fluids, statics and dynamics, and manufacturing."
A well-trained software engineer will be prepared to deal with alien rule systems. The good ones can learn the structure of a new programming language in an hour, the rules in a weekend, and become reasonably fluent and even creative within a week or two. This kind of skill is part of why I have been thinking that engineering skill in limited highly-controlled nanoscale domains could develop quickly. As long as what happens is visible and repeatable, it's quite possible to learn whole landscapes of interactions between very intricate and complex system components, developing and redeveloping hypotheses and techniques on a minute-to-minute basis.
The level of training described here approaches the problem from the opposite direction. The author expects that students will be able to learn enough from theory to become proficient at nanoscale exploration and design--not just able to plug numbers into formulas, but able to intuit how things work. Once this curriculum is designed and students start graduating from it, we can expect to see predesign of nanoscale machines be both more accepted and more useful. This will accelerate the development of advanced nanomachinery.
The article notes that this is a significant advance from what's currently taught: "Requiring professors of mechanical engineering to take graduate-level refresher courses on these topics is not inconceivable." By contrast, many current "courses of study reflect the technological needs of the Sputnik era or perhaps an earlier time." I'll note that the mindsets of many current technologists--including nanotechnologists--also reflect this.
The article ends on a note that's encouraging to me: "What's more, there should be a strong ethical component to this new teaching paradigm." Both unintended consequences and intentional misuse are invoked.
"There are many questions that we engineers must openly discuss: How could nanostructures or manufacturing of nanostructures be harmful to human health? Are there any environmental effects? Could nanotechnology reveal information that infringes on privacy? If improved health diagnostics and therapeutics facilitated by nanotechnology increase lifespan, what effect would the result have on demographics and productivity? Would this technology be accessible to the whole population, or be available to only a certain segment of our society?"
This list is inevitably incomplete. I would add: "How rapidly can new weapons and countermeasures be designed? Which will be more powerful, offense or defense?" This is not to impose responsibility for all military uses on the technologists; my concern is more practical: no one except the technologists can supply this information. And without this information, a sudden increase in our ability to design weapons could take political planners by surprise, leading to geopolitical instability.
Molecular manufacturing implies cheap exponential manufacturing. (Astonishingly cheap per feature; depending on the chemistry, ultimately even cheap per pound.) This implies economic shakeups--first to industries, ultimately to infrastructures and entire economies. Again, the technologists will have to think about these possibilities so they can tell the economists what to expect.
Usually, when nanoscale technology and molecular manufacturing appear onstage together, I worry about confusion and miscommunication. This publication is different. Perhaps because it accepts molecular manufacturing as a straightforward potential consequence of nanotechnology, it has given advice that is equally relevant to both branches. I hope we see a lot more of this in the future.
UPDATE: See our entry on "Mechanical Engineering & CRN".