Difference between revisions of "Superlubricity"
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Revision as of 16:02, 16 December 2013
Superlubrication is a state of extremely low friction that occurs when two atomically precise surfaces slide along each other in such a way that the "atomic bumps" do not mesh or more precisely when the lattices distances projected in the direction of movement are maximally incommensurate.
exapmples:
- two coplanar sheets of graphene relatively rotated to one another
- two fitting coaxial nanotubes
- diamondoid molecular brearings and other DMEs with sliding interfaces.
If AP surfaces surfaces are designed or aligned to not mesh the "perceived bumps" become lower and their spacial frequency becomes higher. If the surface pressure isn't extremely high the characteristic thermal energy kBT can become a lot higher than the bumps energy barriers. Thus the friction becomes so low that e.g. an unconstrained DMME bearing starts turning randomly in a brownian fashion.
