Superlubricity is a certain phenomenon in which friction can vanish almost completely. Superlubricity occurs when two crystalline surfaces slide over each other in dry, incommensurate contact. It is an effect that has been already suggested in 1991 but has recently been measured with great accuracy between two graphite surfaces. One should note that the similarity of the term superlubricity with terms such as superconductivity and superfluidity is misleading; other energy dissipation mechanisms can lead to a finite (normally small) friction force.
The atoms in graphite are oriented in a hexagonal manner and form an atomic hill-and-valley landscape, which looks like an egg-crate. When the two graphite surfaces are in registry (every 60 degrees), the friction force is high. When the two surfaces are rotated out of registry, the friction is largely reduced. This is like two egg-crates which can slide over each other more easily when they are "twisted" with respect to each other.
External links
Super Lubricity of Graphite (http://www.physics.leidenuniv.nl/sections/cm/ip/group/PDF/Phys.rev.lett/2004/92(2004)12601.pdf) (research paper in PDF format)
This superlubricity phenomenon occurs when two surfaces have crystal lattices which are in incommensurate contact, meaning that the crystal arrangement is such that only a tiny minority of the atoms on the surface come in contact with the opposing surface, generating a vanishingly small amount of friction.
Superlubricity was discovered when physicists studied, at very high precision, the friction force between crystal surfaces.
Superlubricity and its study is a relatively recent field, brought up in 1991 but not studied much in the meanwhile.
Superlubricity is a certain phenomenon in which friction can vanish almost completely.
It is an effect that has been already suggested in 1991 but has recently been measured with great accuracy between two graphite surfaces.
One should note that the similarity of the term superlubricity with terms such as superconductivity and superfluidity is misleading; other energy dissipation mechanisms can lead to a finite (normally small) friction force.
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