Brownian technology path
An advanced level of nanotechnology that do not exploit machine phase but thermal movement instead chemistry ...
It will evolve parallel to the mechanosynthetic technology levels I to III and may interact with them in unexpected and yet unpredictable ways.
Richard Jones [1] is someone looking out in this direction.
[Todo: add description ... about speculative advanced biomcompatible area - also optics magnetics electronics and so forth]
A maybe relevant book: [2]