Assembly levels

The assembly levels describe how an advanced productive nanosystem of technology level III will be organized. They constitute a greatly implementation agnostic scheme for the organisation of an advanced productive nanosystem on the bottommost levels.

Since waste is a serious danger of this potentially clean technology a special focus on recycling is taken here.

Note that the used abbreviations in italic are newly proposed terms.

Level 0: (preparating 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.

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 assembling)

Here level I Diamondoid Molecular Elements (DMEs: DMMEs & DMSEs) are assembled to bigger non disassemblabel microcomponents. 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 microcomponents ready for assembly level III are complex or simple conglomerates of many small DMEs. The step from assembly level II to III is the soonest point where product parts can be expulsed to a non vacuum environment. Expulsion requires that all non encloded unterminated radicals that should remain in the final product must be sealed. The consequent ban of irreversible surface interfaces makes the creation of monolithic non-modular non-reusable structures harder. (Finished microcomponents must only use interlocking or weak VdW sticking for interconnectivity.) Microcomponent expulsion sets a clear line preventing inter-mixture between assembly level II and III. For certain products (e.g. diamond single crystals) it would be necessary to defer product expulsion to higher assembly levels. Metamaterials from passivated microcomponents should be capable of fulfilling almost all our needs though.

Enclosed radicals may be used for locking mechanisms, springs, energy- and data-storage.

Recycling: In this assembly level surface interfaces of DMSEs are "welded" together. This step in most cases 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 microcomponents so that they remain recomposable later-on even after they where shuffled. Open documentation will also improve chances for reuse and thereby help to minimize biosphere pollution.

Since at this level only whole DME blocks are handled most overhangs should be "printable" with only three degrees of freedome.

Level IIb: (component tweaking)

Finished level II microcomponents 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 microcomponents 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.

Recycling: 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" products 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. One can think of convergent assambly as putting microcomponents together from the leaves to the root of an octree.

Todo: Find out the advantages of convergent assembly over direct assembly. (It's not speed.) They are mentioned but not really explained here: [1]

Recycling: 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.

Note: do not confuse convergent assembly with exponential assembly.

Notes:

All assembly levels but IV are visible in the official productive nanosystems video [2]. Note that there the airlock step(s) is/are not shown. In E.Drexlers new book "Radical Abuncance" [add ref] 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 (level IV). Note that for recycling one has to deal with dirt at least on the products surface in any way. An "isolation till finished macroproduct" approach would further allow intermixing for Level II & III and thus allow for undissasemblable unrecyclable makroproducts like one big diamond crystal. Such products may only be of interest for maximum performance stuff (military interest, .. ?)

A very 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 APM systems one can take a range of countermeasures starting in their inherent design and buildng up with additional functions. Very desirable would be some kind of global microcomponent redistribution system parallel to our current water supply.