Bootstrapping methods for productive nanosystems

A nanofactory as far term target needs the parts of a nanofactory to make another identical or improved nanofactory.
There's a chicken egg problem here.

Outdated! – KSRM type molecular assemblers

An early idea were molecular assemblers as in the book KSRM. A by now outdated concept!
These were a self suggesting analogy to living cells.
Slightly deeper technical analysis found this approach to be
neither good as far term target nor feasibly as means for bootstrapping.
For details see page: Why ultra-compact molecular assemblers are too difficult

Impatience & pushing too hard:
=> ultra-compact self replication (impossibly difficult for bootstrapping context)
=> no side products along the development path (limiting funding options)
=> overexpectations and disillusionment (repeating cycle)

KSRM assemblers were strongly associated with the direct (to advanced gemstones) path.
But there are also gradual approaches for the direct path too.
Gradual approaches are not limited to the incremental (over foldamers) path.

Gradual approaches

Here self replicative capability …

• … can and will be preceded by a lot of varios non-replicative prescaling methods.
  
• … is more an emergent property of a distributed system that takes the size that in naturally needs to have
  for maximal technical and economical feasibility.
  

There is a focus on gradual improvements on the parts of currently existing technology
that are most critically necessary and most relevant for getting to target technology as soon as possible.

Doing so eventually may lead to a self emerging highly distributed self-replicative capabilities of the system as a whole.
Similar as human technology is self replicative a a whole. Just that this will be all on a single chip.

The task here is to identify these technologies and improve on them in a focused way.
so they are ready when they are needed.

Direct path

Bottom up

High level abstract pathway illustration. With a focus on the direct path here.

SPM sensing, quantum sensing and eventually quantum compute as high value ultra low atom count early products.

Possible high level sequence of technological capabilities (crude sketch):

• (A1) Prototyping of early primitive mechanosynthesis. See also "mechanosynthesis" in general.
• (C) Development of early simple crystolecular mechanisms and early simple crystolecular building blocks as basis.
• (B1) Prototyping of pick-n-place (or better stick-n-place) assembly of pre-mechanosynthesized crystolecules.
• (C) Development of macroscale distances transfer between nanosystems for crystolecules and their still small assemblies.
  Finding the same nanoscale spot again quickly and nondestructively.
• (S) Pre-replicative scaling at the macroscale (more SPM stations, improvements to SPM systems, speedup somes after sufficient reliability though).
• (C) Development of larger subsystems like actuator units and vairious IO solutions (challenges waiting here)
• (A2) Development of nanoscale positional stage subsystem components for mechanosynthesis (not to confuse with KSRM type assemblers, just the stage mechanics and smaller)
• (C) Development of rail and/or frame systems for combining sub-system components modularly, maintainably, IO accessible observably
• (B2) Development of nanoscale positional stage subsystem components for crystolecule assembly
• Arrival at early diamondoid nanosystem pixel (direct path) like systems.
• (S) Finally getting self replicative capability as emerging property.
  Finally crossing the technological percolation limit towards there.

Notes on reaching self replicative capabilities:

• When reaching self replicative capabilities these (for acessibility nanoscale flatly layed out systems) may already be quite big in area (perhaps many many square microns at least,perhaps even nearing square mm scale).
• Self replication will be sketchy and fragile at first. Barely fulfilling the conditions of the replication pentagon over significant amounts of space and time. This is good for safety but also means that arrival at emergent self replicative capabilities does not mean instantly availably perdonal nanofactories for everyone on the planet even from the technical side alone.

Legend:

• (1) … macrorobotics to nanoproducts
• (2) … nanorobotics to nanoproducts
• (A) … maniputating atoms and small molecules
• (B) … manipulating bigger parts like crystolecules and molecular assemblies
• (C) … increase in capabilities
• (S) … scaling

There is a quite good chance that progresses on the incremental (over foldamers) path side
progress so far that mixed path approaches become feasibly.
Integartion of crystolecules as stiff cores in foldamer structures or (perhaps less likely) vice versa.

Top down

This coverage is generalizing it a bit also covering tools at larger scales that may help in more indirect ways
beyond bridging the gaps by creating an overlap in scales.

• Naoscale pattened deposition via electron beam lithography (EBL) made masks may help circumvent limits in codepositability of feedstocks & co onto sample surfaces.

• MEMS may help in improvements on SPM microscopy, though current focus there seems to be focus on parallelity and higher scanning speeds when most important would be a focus on using gains from scaledown for improvements on reliability first.

• Nanoelectronics:
  Cutting edge resolutions are hardly available fur custom chips, ans the numbers are chating a bit factoring in cababilities gained from goint 3D multilayer.
  Implosion fabrication for electrical contacting: Only bulk solid electronic structurs, while cheap and small the unusual (druied gel) surface and depth beneath that surface might likly be an issue. Fundamental research there.

• There is the idea of exponential assembly. It seems quite challening with a lot of parallel open loop control needing very reliable systems.

Incremental path

Bottom up thermally driven self assembly

Thermally driven assembly excels at massive parallelism but
today's capabilities in artificial thermally driven assembly are very limited in
the second critical requirement that (as already mentioned) is:
Total adressability over large size scales. See: Termination control

One of the prime first objectives is thus to scale this addressability for thermally driven assembly.
In this regard there has been some progress in convergent self assembly of structural DNA nanotechnology.
Stiffness of these SDN structures is very low though and there is no positional atomic precision.
There is only topological atomic precision.

As of 2025 there is some progress in with stiffer protein structures too.
(wiki-TODO: Fins paper about protein carpoentry and reference it here.)
In terms of termination control capabilities are still quite limited compared to SDN though.
Some proteins seem to have have true positional atomic precision in their packed backbone ebven at room temperature.
This does not hold for their sie chains though. At least not for natural side chanins with
many weakly constraint rotational degrees of freedom.
Integrating artificial stiff side chains (including spiroligomers) is technically and economically difficult.
Stopping here as digressing towards the fat finger problem.

Bottom up positional assembly on more advanced phase of incremental path

Beyond only thermally driven selfassembly alone. That is with mixed assembly methods.

Foldamer 3D printers

This includes the scaling approach of expanding the kinematic loop
which leads to the concept of foldamer printers.

foldamer printers would requires already sufficiently scaled up thermally driven assembly such that

• such foldamer printers can be self-assembled
• parts for these printers to semi positionally assemble can be pre-self-assembled

foldamer printers would enable:

• the printer making parts from better materials for an eventual next gen printer
• the printer making parts for eventual larger positional assembly structures

• In the foldamer printer concept there is both thermally driven assembly and positional assembly involved.
• Eventual introduction of [[diffusionless selfassembly] for

The nanoscale foldamer based printers being fully self assembled would make production of such devices scaleable. Thereby giving some positional assembly skills at scale. But the scalability here is without large scale addressability.

Foldamer pick and place robots

foldamer pick and place robotss would requires already sufficiently scaled up thermally driven assembly such that

• such devices can be self-assembled
• the parts for these devices to pick and place can be pre-self-assembled

An idea here is to go for less compact replication on the second assembly level.
rather than the ultra compact self replication on the first assembly level that
is present in the outdated concept of molecular assemblers.

See: RepRec pick and place robots

If parts eventually become big enough in the assembly hierarchy of mixed convergent assembley then direct manipulation with top-down manufactured MEMS devices might become possible.

Printer or pick and place robot - which first

This is hard to say. These two seem to lie on two somewhat orthogonal axes on the technological capability landscape. Both require a focus on scaling technological capability in thermally driven self assembly.

• Foldamer 3D printers - put a focus on material stiffness improvement and material diversification
• Foldamer pick and place robots - increases the focus on scaling technological cabability in thermally driven self assembly

Top down – incremental path

Bridging the gaps in scale:

• MEMS: Products of hierarchical selfassembly may soon come close to overalp in scales with MEMS manipulator devices. The SDN structures may be too soft and fragile though. Unclear. Also there might be a lack of interest in doing such experiments.

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Generalized to being indirectly useful:

• Microfluidics: An excelllent match for incremental path efforts. (wiki-TODO: Make page on the transflooder idea eventually somewhen.)
• Specialized resin high resolution 3D printing for microfluidics.

Misc

List of non self replicating bootstrapping tools

• bottom up: fully parallel (and hierarchical) self assembly of atomically precise chemically pre-produced building blocks
• top down: conventional photolithographic methods (MEMs)
• exponential assembly – somewhat of an oddity – the glue between bottom up and top down? – time will tell
• nanoscale masks for patterned deposition (produced by electron beam lithography)

List of non self replicating scenarios

• non compact self replication – as self emerging highly distributed self-replicative capabilities
• medium compact self replication on the second assembly level
• ultra compact self replication via molecular assemblers (outdated since hellishly difficult and very inefficient)

See main page: Self replication

What needs to be done

To produce macroscopic amounts of atomically precise structures that …

• … do not only have nanoscale feature sized (like simple molecules or protein medicines - we can do that today) but rather eventually
• … do have (atomically precise) features at all sizes scales all the way up to the macroscale

… there needs to be a combination of …

• … an introduction and eventually exponential growth towards massively parallel means of manufacturing.
• … an establishment of full location adressability over increasingly large size scales. Growing repetitive crystals is easy.
  See: Termination control

Beside that on the side of the incremental path stiffness of used materials need to be continuously improved to:

• get positional atomic precision not only topological atomic precision
• get to high performance materials and swift production speeds

There are at least three independent orthogonal axes where technological capability can be judged by and scaled along. These are:

• Hierarchical selfassembly and once more advanced Convergent selfassembly levels
  (like experimentally demonstrated in SDN: bricks to blocks then blocks to multiblocks)
• Technology level entagling two things:
  – Material stiffness (SDN, protein, stiffer stuff) and
  – Degree of introduction of positional assembly aspects

Related

• Up: Where to start targeted development
• Bootstrapping atomic precision
• Pathways to advanced APM systems – Incremental path & Direct path
• Bridging the gaps
• Thermally driven assembly
• Exponential assembly
• Molecular assembler – not a good bootstrapping method

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• Dynamic rebootstrapping of upper convergent assembly levels

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• Expanding the kinematic loop

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• Non atomically precise nanomanufacturing methods

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• Self replication