Atomically precise slide bearing
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Up: Atomically precise bearings
Graphic by Eric K. Drexler -- Citation: "Symmetric molecular bearings can exhibit low energy barriers that are insensitive to details of the potential energy function" [1]
Erik K. Drexlers superlubricating "big bearing" - This is a photo of a 3D printed model. See: http://www.thingiverse.com/thing:631715
Atomically precise slide bearings are bearings with:
- all surfaces being atomically precise and sufficiently nonreactive (See: nanoscale passivation)
- atomic bumpiness tuned for incommensurability – See: superlubricity
- dry running – no lubricants – (atoms in lubricants would be like gravel at these scales)
- no hollow spaces where dirt could get caught in & (redundantly) typically operating in a sealed PPV environment
Contents
Pros & Cons
PROs / Advantages:
- can be very small and compact
- can have extremely low friction for small speeds 1mm/s and below
Note: Choosing slow speeds in productive nanosystems is a viable (and proposed) option due to
the scaling law of higher throughput of smaller machinery.
CONs / Disadvantages:
- significant friction for moderate speeds ~1m/s
- very high friction for high speeds
Dynamic friction scales quadratically with speed. 10x speed 100x friction.
And vice-versa as the flip side of the coin.
2 Strategies for reducing friction for higher speeds – in bigger bearings
The design principle of Infinitesimal bearings can help for higher speeds
but going for atomically precise roller gearbearings too in the case of larger scale bearings
(assembly level 2 and above in productive nanosystems) may be advisable.
Related
- Examples of diamondoid molecular machine elements
- Alternative: Atomically precise roller gearbearings
- Infinitesimal bearings
- Superlubricity
- Absence of wear in atomically precise bearings
- Deliberate inclusion of snapback elements can make an intentional high friction damper element
External links
- Wikipedia: Plain bearing (aka sleeve bearing)
References
- ↑ Drag mechanisms in symmetrical sleeve bearings: Drexler, K. E. (1992) Nanosystems: Molecular Machinery, Manufacturing, and Computation. Wiley/Interscience, pp.290–293.
