Yesterday, I described the atomically precise manufacturing (APM) system planned by Jim Von Ehr of Zyvex. At first sight, it's pretty exciting. Building 3D shapes out of covalent solids with every atom exactly where you want it -- isn't that the holy grail of molecular manufacturing?
No, it's not, but it's not trivial to explain the difference. And that's why, as the world gets closer to molecular manufacturing, it may be easy for many people to assume we've reached the goal when we really haven't.
Atomic precision appears necessary for some very important capabilities and techniques that will combine to make molecular manufacturing so powerful. For example, imprecise surfaces can't slide past each other very well; friction is high, pieces break loose, and it just doesn't work very well. But certain precise surfaces, positioned correctly, can have extremely low friction and zero wear (this is called superlubricity, and it's been observed in graphite).
Another capability that's important for molecular manufacturing is the ability to use a fully computer-controlled manufacturing system to build duplicates on command from inexpensive feedstock. Without this capability, the cost of products will be limited by the cost of the manufacturing system, and today's manufacturing systems tend to be expensive; but if the cost of the manufacturing system can itself be diluted over many copies, then the cost of the products may approach the cost of raw materials.
A third capability is building functional systems. With interlocking shapes, it's possible to build sensors, computers, kinematic systems, energy storage systems, etc. -- but all of that will require additional research.
From a technical point of view, it's clear that an APM system would be a big step toward a full-fledged molecular manufacturing capability. But I have to wonder whether a successful APM system would serve to accelerate or to retard the development of molecular manufacturing. Over the past few years, we've seen a lot of nanotech researchers point to various milestones and say, in effect, "This is the goal of nanotechnology; this is as far as we need to go."
Of course that's not the case; there is a vast difference -- in technology, functionality, and value -- between nanoscale structures and complete products with trillions of high-performance nanoscale machines. Until now, it's been easy to see that difference; in fact, the contrast has been so great that molecular manufacturing has seemed implausible to a lot of nanotech researchers.
But as we reach the point where mainstream nanotech researchers can speculate about building large, atomically precise molecules on command, skepticism may give way to blurriness without ever achieving clarity. It might be easy then to pick any particular level of capability and say, "See, that's what those Drexler people were talking about, and we're doing it, so there's no need to look further." (Let me be clear: I'm not accusing Jim Von Ehr of this. I'm thinking instead of other nano leaders whom we've already seen playing this bait-and-switch game.)
An important task of CRN will be to work toward educating science writers and others on the difference between molecular design, functional nanosystems, and other near-term technologies, and full-blown molecular manufacturing.
If the seeds of confusion are allowed to take root and grow, researchers, policymakers, and stakeholders may lose sight of the real potential of molecular manufacturing: non-scarce, rapid, inexpensive, general-purpose manufacturing of radically high-performance products. One result of that might well be a delay of several years in the arrival of molecular manufacturing. But another result would be the continuing near-total lack of preparation for molecular manufacturing's disruptive effects.