Although timelines are always hard to predict, an attractive feature of self-assembly approaches is that they involve less discovery and more design. Zyvex is gambling — and it may prove to be a very good gamble — on the discovery of new chemical processes involving small molecules. Processes of this sort may be similar to one another, but each is substantially unique. Although experimentation and discovery can be guided by well-informed guesses there is no systematic way to design one.

In macromolecular engineering, by contrast, structures are made by combining many pieces in a systematic way, and this process creates a vast, combinatorial design space. This makes design possible, though supplemented with a lot of trial-and-error in the early days. If the operating principles and general structure of an intended product are sufficiently similar to those of known systems, there can be good reason to be confident that the design space contains many structures that would satisfy the product’s functional specifications. Confidence in feasibility still doesn’t provide a timeline, of course.

controlled the probe’s position in three dimensions to better than 40 picometers (1 nanometer = 1000 picometers) over 100 seconds.