How small scale friction shapes advanced transport
Contents
Transport in general
The further one wants to transport stuff and
the smaller the stuff one wants to transport
the more one wants to bunch and link this stuff together before the transport via some "pre-transport".
This minimizes the shear slide motion surface area between the parts-to-transtort to the static environment
for the majority of the transportation distance, and thus it minimizes the friction losses.
Naturally the distance of the "pre-transport" (and the possible "post-tranport") needs to be minimized.
(TODO: Work out the math here.)
If the main transport distance gets down near to the same order of magnitude of the pre- and post-transport distance then at some point one falls below a threshold below which it does not energetically pay of to do this "pre packaging for transport" any more.
For a general transport of parts that are not necessarily designed to fit together there needs to be a solution of transport containers (a bit over the size of the parts to transport) that do fit together (providing a shape adapter function).
Short range transport in Nanofactories
In a layered thin film chip like nanofactory design (as the current concept foresees) this bunching together with a minimal pre-transport path length is ensured. Well, it is better to call it inter-assembly-layer transport here, since there is no main- and post-transport. The main transport would coincide with the pre-transort of the next assembly layer. Well, if one stretches it, one maybe could maybe also see the path the final product takes when in usage (e.g. in human hands) as the a main transport and a recycling disassembly process that potentially happens at some other place else as the post-transport.
Back to topic: In convergent assembly the shortest possible inter-assembly-layer-transport is ensured by well designed convergent assembly. (between assembly layers interdigitating routing layers) (Convergent assembly that needs to heed equivalent layer stacking requirements due friction reducing slowdown at the bottommost levels).
In the case of convergent assembly in nanofactories there is usually no need for transport containers providing an adapter function since the parts are made to fit together and are put together to bigger fragments of the product right away.
At higher assembly levels and consequently bigger size scales sliding surface areas become very low. Also there now is plenty of space available that can be filled with infinitesimal bearings to reduce friction levels even further.
One may want to now trade this extremely low friction to just low friction for something else. One may want to trade it for a certain principle that can beef up assembly speed. Namely part streaming designs.
Part streaming designs are remotely similar to todays 3D printers where there is a continuous feed of plastic into a moving manipulator, but here with discrete parts that are themselves already pre-assembled from smaller discrete parts.
The idea is to stream the previous level pre-assembled current level unassembled parts through the manipulators arms interior (or on the manipulators arms surface) directly towards the end effector. This way the manipulator does not need to constantly go back and forth to pick up new parts while still retaining all of its general purpose capabilities. (Unlike lowest assembly level mechanosynthetic assembly where there too is streaming but no general purpose capabilities).
At the macro scale assembly levels (e.g. playing dice size to room size) one could even imagine highly dexterous tentacle like manipulators. Educational models may forgo on the usage of UV and further light absorbing nanomachinery protecting functionality and operate at a slowed down pace such that one can follow the parts wandering through with ones bare eyes.
Streaming designs may be sensible starting relatively early in the assembly level stack. That is as early as microcomponent assembly to product fragments (). At this size levels streaming would look much more mechanical though. There's simply not enough space yet for the aforementioned organic looking tentacle like designs. No space for thick swaths of infinitesimal bearings that are combined with advanced mechanical metamaterials that emulate elasticity.
The "productive nanosystems" concept video features streaming designs at the microcomponent to product fragment assembly level. There is no need to putting them at the end of the assembly level stack (as shown) though.
A tentacle streaming designs at the very topmost macroscale assembly is a quite conspicuous deviation from the classic more basic nanofactory thin film design. It's important to realize that despite the change in looks, proper design principles for nanofactories the we already have learned are not being abandoned.
Some speculations
Streaming designs can be combined with:
- (1) The classical pick and place design.
Just make the tentacle manipulator pick up a part from the sub assembly cell it comes out from instead of letting it draw from its streaming supply - (2) A parallel extrusion design.
As if it where the last and uppermost assembly layer.
This may not make much sense in the context of first virgin assembly. Just as it is the 3D printing processes of today, with a cracked open cross sectional plane one can have access to just about everywhere. It may make more sense in case of product reconfiguration, where putting just a few parts from one hard to reach spot to another hard to reach spot by some complex manipulator paths may be quite a bit quicker than taking the whole thing fully apart. Completely down to its rather small base parts.
Long range transport for recycling
The necessity of long range transport also crops up in the context of recycling. Since what person A does not need anymore may be needed by person B that sits somewhere quite far away.
Again to reduce friction losses, for long range distance transports one may want to bunch parts (of all size scales) together to even bigger "parcels" before "shipment".
Microcomponents are the most versatile parts in the assembly level stack. They are simultaneously reusable and still rather fundamental (not as fundamental as crystolecules, but fused crystolecules lack in recyclability). Due to their versatility microcomponents may be the most desirable to send/ship to other far away places over long range distances where it's from a friction minimization standpoint better to have parcel sizes that are quite a bit bigger than microcomponents. Bigger parcels require and equate to bigger diameter of the transportation lines.
Taking a wild guess for diameters one could maybe think of:
- millimeter scale lines for many cross city scale (intercity) transport lines
- centimeter diameter lines for many cross country scale (international) lines
- decimeter diameter lines for many cross globe scale (intercontinental) lines
One may imagine those lines (superlube tubes) not entirely unlike conventional tube mail. Just that there is neither air nor vacuum in there. It would be a solid state stream of one very very long flexible "parcel". A "parcel" made up out of many very small transport containers. Containers that link together with enough elasticity emulating metamaterial capabilities, such that they can go around the necessary curves in the lines. Also the "parcel" (flex-pack-stream?) would be lubed in a quite thick shell of infinitesimal bearing metamaterial. (Getting infinitesimal bearing metamaterial to emulate elasticity at the same time might be quite difficult to design.)
To get microcomponents out of nanofactories and suitably packaged up in that "solid state stream" for transportation, one needs to make the nanofactories (possibly specialized ones?) assemble the solid state micro-parcel stream just like any other product. There is no need to somehow tap nanofactories "sidewards" between the assembly levels, as one may think. That won't work.
Excess material will need to be managed in caching depots. Not entirely unlike digital memory caches in computer architecture just much bigger (storehouse size) and with physical immutable contents instead of mutable bits and bytes.
If the requested quantities of some type of microcomponent are too high to being fulfilled by caches nearby caches farther away need to be used too. Old stuff never used by anyone anymore needs to be disposed of in a safe way with zero release of waste (e.g. burning, dissolving, ...)
Beside transport of microcomponents there is no reason for not having something even more similar to conventional tube mail. Still superlubricated but this time with real macroscale capsules where one can put in non gem-gum products too like e.g. bananas to give a completely arbitrary example.
