Definitions of nanotechnology are getting broader all the time. A draft definition recently crossed our desks, something on the order of "The study of things too small to see." This is of course far too broad, and does not indicate what is special about nanotechnology.
But what, exactly, is special about nanotechnology? What collective observation -- let alone formal definition -- can be made about a loose association of fields as diverse as fabricating computer chips, making movies of proteins in action, and analyzing the performance of future nanofactories?
The best definition for 'nanotechnology' that we could come up with is:
Engineering of functional systems at the molecular scale.
It goes without saying that this definition will not satisfy everyone. However, it includes most kinds of nanotech that we can identify, while implying the novelty of the research and development.
To anticipate a few objections:
- Many kinds of nanotech are not involved with molecules, but with non-molecular structures. However, "molecular scale" refers to a (broad and fuzzy) range of sizes rather than requiring actual molecules.
- "Functional systems" seems to exclude passive nanoscale structures. However, we think this is not actually a bad thing. A structure without a purpose is just a curiosity; conversely, a system can be functional without being active. A buckytube in a composite has the same function as a girder in a bridge.
- By specifying "engineering," the definition excludes random discoveries. But by the time a discovery becomes a technology, it will have advanced far from the initial observation or insight.
- "Systems" might seem to be restrictive, but it's hard to imagine how a molecular-scale object could be useful without being part of a system--even if only a system of measurement.
- Modern microscopy studies the nanoscale without necessarily being built out of molecular-scale systems. However, it seems appropriate to leave tools such as electron microscopes in the gray area, since they existed long before "nanotechnology" was conceived. Proximal probe microscopes do, of necessity, include molecular-scale components.
We like this definition because it encompasses most of today's nanoscale technologies, while simultaneously pointing the way toward increasingly intricate, functional, and active nanosystems. Of course, the nanosystems that we at CRN are most interested in are productive nanosystems: molecular-scale devices engineered for the purpose of building more molecular-scale devices.
Unless one of our astute readers finds a significant flaw in this definition, we will propose it as a suitable definition for situations where authors want to include both nanoscale technologies and molecular manufacturing in their discussions of 'nanotechnology'.