No self-replicating ones
This is not about nanobots (especially not the self replicating type).
While self replication nanobots (aka molecular assemblers) where an early idea that naturally suggested itself (it was originally presented in the book "Engines of Creation" 1986) slightly less old (and much less known) methodical work ("Nanosystems" 1992 - same author) strongly points to nanofactories as a much better target.
- The self-replicating molecular assembler concept is outdated.
It was superseded by Nanofactories since before 1992!
(Details: Molecular assembler)
Nanobots have traits associated with them that have nothing to do with current concepts for advanced productive APM systems. Most notably:
- living & evolving
- insatiable, "metabolize" just about anything -- (see: Omnivorous nanobots)
- super dangerous - the accident is unavoidable and cataclysmic
Few non-self-replicating ones
Non self-replicating medical nanobots, utility fog and similar concepts are still not outdated but:
- As especially difficult to design systems advanced mobile nanobots (the of the diamondoid kind) lie even beyond the far term target of Nanofactories. And the development of Nanofactories is more of a main focus here on this wiki than things that lie out even further beyond them.
- They make up only a very tiny part of the possible product space. Most products will be devices made from arrangements of highly specialized mechanical metamaterials. Just like computers do not consist out of "computronium" advanced products will not consist out of "nanofogonium".
Advanced products out of complexly intertwined metamaterials rarely (if at all) make it into popular fiction probably because:
(a) the concept is barely known and
(b) it would require in depth explanations.
And Explanations in an area where even many "experts" (experts in fields that are topically near to APM) are not aware that there is stuff that already can be known with high confidence (see: exploratory engineering). With SiFi producers totally lacking awareness over this void of as of yet (2018) they never treated mechanical metamaterials. There's not even motivation for them to fill this void with complete nonsense. Which is probably a good thing.