Difference between revisions of "Dissipation sharing"
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| − | Dissipation sharing is a technique enabled through smart usage of [[machine phase]] that allow to far surpass the efficiencies seen in already pretty efficient biological solution based systems. <br> | + | |
| + | This page is about a method to hyper-optimize energy efficiency in advanced [[piezomechanosynthesis]]. <br> | ||
| + | |||
| + | == Disclaimer == | ||
| + | |||
| + | It is questionable whether the idea presented here will be relevant, <br> | ||
| + | given a lot of other loss mechanisms can be quite big like: | ||
| + | * Losses from dynamic [[friction]] | ||
| + | * Losses in [[piezomechanosynthesis]] and [[chemomechanical conversion]] – ([[inter system crossing]]) | ||
| + | * losses in imcomplete recuperation of entropic energy | ||
| + | |||
| + | For dissipation sharing to become relevant <br> | ||
| + | the setting will certainly need to be an already highly optimized system. | ||
| + | |||
| + | == Intro == | ||
| + | |||
| + | Dissipation sharing is a technique enabled through smart usage of [[machine phase]] that <br> | ||
| + | allow to far surpass the efficiencies seen in already pretty efficient biological solution based systems. <br> | ||
To the authors knowledge "dissipation sharing" is a novel idea here presented for the first time. | To the authors knowledge "dissipation sharing" is a novel idea here presented for the first time. | ||
| Line 52: | Line 69: | ||
Introducing mechanical advantage (gear train transmission) as soon as possible to gain high virtual stiffness in the background may be a feasible strategy. | Introducing mechanical advantage (gear train transmission) as soon as possible to gain high virtual stiffness in the background may be a feasible strategy. | ||
| + | |||
| + | === Dissipation from vibronic de-excitation (quantum effect) === | ||
| + | |||
| + | If spins don't line up antiparallel such that covalent bonds can be formed then first an [[inter system crossing]] transition is needed. <br> | ||
| + | Intersystem crossing still leaves an electronically slightly excited state. So it is followed up by "vibronic de-excitation" (conversion to phonons aka heat). <br> | ||
| + | Vibronic de-excitatin is a dissipation mechanism that may be hard to control or may not be controllable at all (to investigate). | ||
| + | |||
| + | Boosting [[inter system crossing]] speed can reduce [[dissipation]] but <br> | ||
| + | that does not seem to effect the vibronic de-excitation (to inversigate). | ||
== What if you don't pay fully? == | == What if you don't pay fully? == | ||
| Line 65: | Line 91: | ||
== Misc == | == Misc == | ||
| − | Possible effect of location of deliberate dissipation elements | + | Possible effect of location of deliberate dissipation elements (speculative): |
| − | * too low down wastes energy? | + | * too low down –> wastes energy? |
| − | * to high up causes oscillation problems? | + | * to high up –> causes oscillation problems? |
== Related == | == Related == | ||
| + | * '''[[Lagrangian mechanics for nanomechanical circuits]]''' | ||
| + | * '''[[Drive subsystem of a gem-gum factory]]''' | ||
| + | * [[Lagrangian mechanics for nanomechanical circuits]] | ||
| + | * '''[[Piezochemical mechanosynthesis]]''' – [[Mechanosynthesis core]] | ||
* [[Exothermy offloading]] | * [[Exothermy offloading]] | ||
* [[Energy recuperation]] | * [[Energy recuperation]] | ||
* [[Low speed efficiency limit]] | * [[Low speed efficiency limit]] | ||
| − | |||
| − | |||
* [[Reversible actuation]] | * [[Reversible actuation]] | ||
| + | * '''[[How macroscale style machinery at the nanoscale outperforms its native scale]]''' | ||
---- | ---- | ||
* [[How gem-gum factories link to deep mysteries of the universe]] | * [[How gem-gum factories link to deep mysteries of the universe]] | ||
* [[Philosophical topics]] | * [[Philosophical topics]] | ||
| + | * [[Arrow of time]] | ||
== External Links == | == External Links == | ||
Latest revision as of 12:03, 14 April 2024
This page is about a method to hyper-optimize energy efficiency in advanced piezomechanosynthesis.
Contents
- 1 Disclaimer
- 2 Intro
- 3 In machine phase (A) friction from superlubrication is not a disadvantage since it's far over-compensated by gains elsewhere
- 4 No possibility to receive energetic "exchange money" in diffusion based systems (B)
- 5 The minimum price to pay to never go backwards
- 6 Sticking together comes cheaper -- dissipation sharing
- 7 The limits of sharing
- 8 What if you don't pay fully?
- 9 Conclusion
- 10 Misc
- 11 Related
- 12 External Links
Disclaimer
It is questionable whether the idea presented here will be relevant,
given a lot of other loss mechanisms can be quite big like:
- Losses from dynamic friction
- Losses in piezomechanosynthesis and chemomechanical conversion – (inter system crossing)
- losses in imcomplete recuperation of entropic energy
For dissipation sharing to become relevant
the setting will certainly need to be an already highly optimized system.
Intro
Dissipation sharing is a technique enabled through smart usage of machine phase that
allow to far surpass the efficiencies seen in already pretty efficient biological solution based systems.
To the authors knowledge "dissipation sharing" is a novel idea here presented for the first time.
For brevity in the following we will refer to
- Advanced gemstone based atomically precise manufacturing system with (A) and to
- more primitive systems based on solution based self assembly with (B)
In machine phase (A) friction from superlubrication is not a disadvantage since it's far over-compensated by gains elsewhere
While in case (A) one has some very small losses due to the friction of the superlubricating bearings compared to completely free since thermally driven transport in case (B) the final deposition of the molecule(fragment) at the target location can be done so much more efficient in case (A) that it easily more than compensates the former disadvantage.
No possibility to receive energetic "exchange money" in diffusion based systems (B)
The problem in case (B) is that the bonding energy of the molecule to the target site is a fixed quantity. (Example: ATP in cells carries around a fixed amount of energy.) If the reactants are not held by manipulator tips the bonding energy cannot be collected/recuperated as "exchange money" by letting the reaction-pull-force do work to some energy storage elsewhere. Instead the "exchange money" is fully thermalized/devaluated.
The minimum price to pay to never go backwards
A little bit of thermalization/devaluation of energy is required though to make sure that the bonding reaction runs reliably forward. For the bonding reaction to run forward reliably the energy pumped into the thermal motions must significantly exceed the quantity kBT.
For a system to run predominantly in one direction (for it to have an arrow of time) the thermodynamic potential for the system must decrease. For solution phase chemistry the appropriate thermodynamic potential is the Gibbs free energy. One needs to devaluate/thermalize free energy.
For a single reaction the energy pumped into the thermal motions must significantly exceed kBT. Beside the obvious thing to lower the temperature (which has practical limits) there's another opportunity to drive down the price. Sharing.
Sticking together comes cheaper -- dissipation sharing
In advanced systems (A) there's a trick (the titular "dissipation sharing") that may allow one to avoid paying the minimum "tax" for every single reaction. One can thereby go to the limits and squeeze out the last little bits of efficiency towards 100%.
In solution based systems (B) reactions are mostly fully isolated from each other. Every reactant molecule has its own degrees of freedom. Stiff machine-phase-systems (A) allows one to link many reactions together. More concretely: Many of the molecular mills are linked together in the background stiffly by one common rotating shaft. This effectively reduces the many individual degrees of freedom for the atom depositions to just a single one. The rotation angle of the main shaft. Only for this one remaining common degree of freedom one needs to still expend/theralize/dissipate an amount of energy >> kBT to ensure forward motion.
The limits of sharing
How many reactions one can can couple together is a highly nontrivial but very important question. (TODO: investigate that) More accurately the question is how far can one stretch the spacial and temporal reach of the degree of freedom of one "virtual reaction". Elasticity modes in the background mechanics (e.g. lowest torsion twist eigenmodes in axles) introduce new unwanted degrees of freedom that need to be fed. Degrees of freedom can decouple the sites of mechanosynthesis into groups of in the worst case just one.
One can think of it like that: If there is enough flex in the axles in the background then even if the far away end is held firmly the reaction site van still fall/snap dissipatively in sharp energy minimum.
(TODO: add infographic)
Stretching the limits of sharing
Introducing mechanical advantage (gear train transmission) as soon as possible to gain high virtual stiffness in the background may be a feasible strategy.
Dissipation from vibronic de-excitation (quantum effect)
If spins don't line up antiparallel such that covalent bonds can be formed then first an inter system crossing transition is needed.
Intersystem crossing still leaves an electronically slightly excited state. So it is followed up by "vibronic de-excitation" (conversion to phonons aka heat).
Vibronic de-excitatin is a dissipation mechanism that may be hard to control or may not be controllable at all (to investigate).
Boosting inter system crossing speed can reduce dissipation but
that does not seem to effect the vibronic de-excitation (to inversigate).
What if you don't pay fully?
Occasionally running backwards a slight bit may be bad for a nanofactory. If the reactions are not fully reversible one might end up in an unknown failure state (atom at wrong location). When progressing with open loop control (manipulators working blindfolded to a good part will be normal in advanced nanosystems) the resulting errors effects may range from irrelevant over performance degrading to fatal for the local subsystem. Depending whether on the location of the error and the degree of consequential errors.
Conclusion
Advanced gemstone based atomically precise manufacturing system (A) operating in machine phase
will be able to do guided placement of molecule fragments much more efficiently than more primitive systems based on solution based self assembly (B) is able to its molecular assembly that is unguided and thermally driven .
Misc
Possible effect of location of deliberate dissipation elements (speculative):
- too low down –> wastes energy?
- to high up –> causes oscillation problems?
Related
- Lagrangian mechanics for nanomechanical circuits
- Drive subsystem of a gem-gum factory
- Lagrangian mechanics for nanomechanical circuits
- Piezochemical mechanosynthesis – Mechanosynthesis core
- Exothermy offloading
- Energy recuperation
- Low speed efficiency limit
- Reversible actuation
- How macroscale style machinery at the nanoscale outperforms its native scale
