Assembly levels
How an advanced productive nanosystem will be organized.
This is a greatly implementation agnostic scheme for the organisation of an advanced productive nanosystem on the bottommost levels. A special focus on recycling is taken.
Contents
Level 0: (prearating tooltips)
Here the tooltips are loaded with feedstock molecules (moieties), sent to level I and return empty to be reloaded again. A closed cycle is a lot more complicated than this suggests. A lot of work has been done here: A minimal Toolset [Todo: add link]
Level I: (DME synthesizing)
Here small diamondoid molecular machine and structural elements (DMEs) are mechanosynthesized.
DMEs are most useful when they are designed to be reusable standard models. In any kind of nanosystem from every type (or set of types) of DMEs an enormous number of identical copies is needed. An example for a set of standard parts is e.g. the set for minimal dynamic systems. For an efficient system lots of specialized building chambers for the different DMEs make sense. This naturally leads to a kind of nanofactory system design.
Recycling: Mechanosynthesis is not reversible. If diamond is used as building material the bound carbon can only be brought back to the biosphere by burning of the DMEs. There are other diamondoid materials that are slightly water soluble and may allow for an unattended route back to the biosphere.
Leve IIa: (sinterface welding & DME assemling)
Here level I Diamondoid Molecular Elements (DMEs: DMMEs & DMSEs) are assembled to bigger non disassemblabel components. They are built in an evacuated building chamber thus their size is limited. They are assembled covalently by pressing compatible sinterfaces together and structurally by pick and place (think of putting rings on rods). To counter the thermal shaking effect (let go of a piece and it josts away instantly) which is prevalent in this size range parts which are supposed to move in the final product are held down by either VdW forces or sparsly distributed covalent bonds (predetermined breaking points) or a second gripper.
Finished components ready for level III are complex or simple conglomerates of many small DMEs. Assembly in level II must seal all unterminated radicals that should remain in the final product. Such enclosed radicals may be used for locking mechanisms, springs, energy- and datastorage. Finished components must only use interlocking (or weak VdW sticking) for interconnectivity.
Recycling: The surface interface welding of DMSEs done in this assembly level is irreversible. For recycling of the whole finished microcomponents it is highly advisable to keep all the outer interlocking mechanisms reversible and to physically tag all components so that they remain recomposable lateron evern after they where shuffled. Open documentation will also improve chances for reuse and thererby help to minimize biosphere pollution. Sidenote for readers knowledgeable in 3D printing: Since at this level only whole DME Blocks are handled most overhangs are "printable" with only three degrees of freedome.
Level IIb: (component tweaking)
Finished level III components might provide some adjustability and or means for functional mechanical testing. General purpouse maintainance units (level II & III) which remain in the final product should be able to operate these functions. And repair/replace/remove them based on the results.
Level IIIa: (component composing)
Here out of components finished in level II structures of arbitrary scale are built. Connections are made via interlocking in an ambiet pressure envirounment. Dirt like chain molecules viruses and dust must be considered. Positional accuracy may be lower than atomic. The connectors restore atomic resolution by guidance. Note that there is a tradeoff between functional-density and module-reusability. The smaller the units get the more fundamental and reusable they will be, but they'll have much interlocking surface eating up quite a lot of otherwise usable volume.
Level IIIb: (component recomposing)
General purpouse maintainance units can recompose components to completely different makroproducts. Compared to rezzing from level 0 this produces considerably less heat and can be done considerably faster. Hopefully a global network of machine phase component redistribution pipes will emerge at some not too late point in time.
Level IV:
An Optional step. Some layers of convergent assembly can be added to boost performance. A level IIIb and IIb system may be included into the product that bypasses Level IV so that products can execute self repair actions while running.
Notes:
All Levels but IV are visible in the official productive nanosystems video. Note that there the airlock step is not shown. In E.Drexlers new book Radical Abuncance the outlined system differs in that it keeps the process in vacuum/noble-gas till the product is completely finished. This design avoids the complexity of dealing with dirt but introduces the complecxity of providing appropriate vacuum at all convergent assembly levels. Note that for recycling you have to deal with dirt at least on the products surface in any way. This approach would further allow intermixing for Level II & III and thus allow for undissasemblable unrecyclable makroproducts like one big diamond crystal or maximum performance stuff maybe even exceeding the needs for spaceflight ( => only of military interest?)
Technical information about productive Nanosystems can be found in the book NANOSYSTEMS
ps: the used abbreviations in italic are proposed by me, whether you adept them is up to you.
pps: In my opinion the most important issue whenever responsibly designing nanomachinery is to aim for best waste avoidance. It does not come for free. The history of plastics show the dangers pretty well. But with nanosystems one can take a range of countermeasures starting in their inherent design and buildng up with additional functions.