Machine phase

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Molecules 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 freedom) such that thermal movement can't move them to unknown places or bring them in an unknown states.

  • Nanosystems 1.2.2.a A machine-phase system is one in which all atoms follow controlled trajectories (within a range determined in part by thermal excitation).

Machine phase is sometimes also called "eutactic phase".
Eutactic means "well ordered". (Not eutectic wich means "well melting").

Why work in the machine phase?

The natural solution to the problem of assemblying products

For the problem of assembling stuff in an efficient fast and controlled ways macroscale robotics is just a natural choice.
And as it turns out almost macroscale style machinery at the nanoscale works even better at the nanoscale that at the macroscale.
(Contrary to what the effects of current day experimental research limitations may seem to imply)

Macroscale "cog-and-gear machinery" is typically in an eutactic phase.
Well there are a few exceptions where a bit of macroscale dystactic phase is involved.
Like e.g. part rattlers forcing parts in the right orientation.

Related notes

Nanoscale crystolecules will be hard to even get off of a crystolecular robotic nanomachinery gripper due to the Van der Waals force being significant.
But once off of an robotic gripper and on onto a perfectly flat surface (with mismatching atomic corrugations)
then they may superlubricatingly skitter around till the get stuck in a random nearby corner.
See: Intuitive feel#Everything is shaky

Releasing single small molecules from eutactic phase to dystactic phase is easier than releasing whole crystolecules which are much bigger (thousands of atoms typically).
This is due to Van der Waals force binding them to the walls being much smaller. So small that it is usually overpowered by the characteristic thermal energy at room temperature.

In fact in some sense PPV is an eutactic phase since all about it is known. We know that it is just completely empty. Ignoring virual particles cosmic rays and such here.
And in some sense the first released small gas molecule into that PPV replaces that PPV with the the positionally unknown and/or quantum dispersed presence of itself.
Creating a dystactic phase. The (intentionally or not) released gas molecule will not stop ballistically bouncing around until it eventually hits an open radical that binds strong enough to not let it go again.

An accidentally into a mechanosynthesis core released gas molecule may end up on a tooltip. Eventually leading to errors in the process of mechanosynthesis.
While accidental gas release can be made very unlikely it's also easily possible to expose plenty of alternative open radical binding sites.
See: Getter grid

Open loop control – Remember where you put your stuff when you operate blindly

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: A light based "nano-camera" isn't possible.
Light has either too long wavelength or it's too energetic and needs too big generation and sensing facilities that are beyond simple nanomechanics.

Energy efficiency

It's also a matter of energy efficiency. Catching a particle from dystactic phase into eutactic phase can "squeeze out" a thermal degree of freedom that contained (according to the equipartitioning theorem) an energy of kBT. Even if that is kept as reversible as possible that energy turnover causes unnecessary losses.

  • dystactic to eutactic catching – DOFs are queezed out – heating
  • eutactiic to dystactic releasing – DOFs fill up – cooling

Related: entropomechanical converters and Diamondoid heat pumps. There this is done on purpouse.

Furthermore some dystatic phases (liquid and gas phase) also impose viscous drag.
That is in the case of when speeds are enforced are above the (typically quite low) natural diffusion speeds.

Machine phase chemistry

Performing chemistry in machine phase it is called machine phase chemistry or mechanosynthesis.
It greatly accelerates reactions rates (compensating lower densities of reaction sites) and one obviously can freely choose where one wants each reaction to occur.

  • Nanosystems 1.2.2.a Machine-phase chemistry describes the chemical behavior of machine-phase systems, in which all potentially reactive moieties follow controlled trajectories.

Partial machine phase in biological and diamondoid systems

When a DMME bearing is fixed on an axle but freely allowed to rotate one can think of this as the bearing being only partly in the machine phase. Though not in a strong sense biological systems sometimes operate in machine phase too. Enzymes binding two reactants at the same time and acting like a vibrating hinge (like chattering teeth) that repeatedly bring the reactants together can dramatically increase reaction rates. This is often described as an increase of effective concentration (waybackmachine) (direct link dead).

In the step from technology level 0 to technology level I bigger purely self assembled sturdy structures may start to provide local machine phase.

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