Brownian technology path
From apm
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]