Machine phase

Atoms moieties and molecular machine elements like DMEs are said to be in the machine phase when they are fixated to a place or fixated to controlled axes (controlled degrees of freedome) such that thermal movement can't move them to unknown places or bring them in an unknown states.

Since assembly at the nanocosm is done blindly it is important to know where you left your things. Thus one wants to work in the machine phase. Searching and grabbing your tools like we do in the makro world does not work. Once one let go of a smaller molecule its as good as impossible to catch it again by grabbing it sterically (meaning with shape not chemical reactivity) one can imagine this as the molecule being supersleazy and superfast. As a sidenote: Light isn't usable at the nanocosm it has either too long wavelength or it's too energetic and needs too big generation and sensing facilities that are beyond simple nanomechanics.

Performing chemistry in machine phase it is called machine phase chemistry or mechanosynthesis. It greatly accelerate reactions rates and one obviously can freely choose where one wants the reaction to occur.