Atomically precise slide bearing

Up: Atomically precise bearings

A simulation of a superlubricatinvg strained shell sleeve bearing. Author Eric K. Drexler

Graphic by Eric K. Drexler -- Citation: "Symmetric molecular bearings can exhibit low energy barriers that are insensitive to details of the potential energy function" <ref name="pdrag"> Drag mechanisms in symmetrical sleeve bearings: Drexler, K. E. (1992) Nanosystems: Molecular Machinery, Manufacturing, and Computation. Wiley/Interscience, pp.290–293.</ref>

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

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

References

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