Tribological Performance of Lubricated Mechanical Systems

Tribology, the study of friction, wear and lubrication, underpins the reliability and efficiency of virtually all mechanical systems in modern industry. In lubricated contacts, a fluid or solid film separates moving surfaces to reduce energy losses, prevent surface damage and extend component life. The performance of these systems depends on the interplay between lubrication regimes—ranging from full-film hydrodynamic lubrication, through mixed lubrication, to boundary lubrication—and surface properties such as roughness, chemistry and texture. Advances in bearing design, high-pressure elastohydrodynamic lubrication, novel lubricant chemistries and surface engineering have enabled ultrahigh-speed machinery, extreme-load bearings and low-friction biomedical interfaces. Emerging two-dimensional materials and ionic liquids offer routes to superlubricity, while bio-inspired hydration lubrication promises near-zero friction in aqueous environments. Optimising these phenomena has global significance: friction and wear account for nearly a quarter of world energy consumption and contribute substantially to CO₂ emissions. Recent developments emphasise multiscale modelling, mechanochemical additive design and adaptive surfaces, forging connections between fundamental science and applications in transportation, energy generation, manufacturing and healthcare.

Research from Nature Portfolio

Recent studies have demonstrated microscale superlubricity between graphene layers under gigapascal contact pressures using chemically grown coatings on microspheres. The resulting friction coefficients approach 0.003, sustained across varying humidity levels, thanks to randomly oriented graphene nanograins that maintain incommensurate contact. Complementary work has directly measured energy dissipation in confined hydration shells between charged surfaces, elucidating how viscous losses in subnanometre water layers account for the exceptionally low friction found in natural joints. These findings advance our understanding of atomically thin lubrication and highlight routes to extend such mechanisms to artificial bearings and biomedical implants.

Tribological Performance of Lubricated Mechanical Systems publication trend

The graph below shows the total number of articles in tribological performance of lubricated mechanical systems across all publications each year (not limited to Nature Index journals).

Technical terms

Tribology: The interdisciplinary science of friction, wear and lubrication in interacting surfaces.

Hydrodynamic lubrication: A regime where a continuous fluid film fully separates sliding surfaces under load.

Boundary lubrication: A regime in which surface asperities interact through adsorbed additive films when the fluid film is insufficient.

Elastohydrodynamic lubrication (EHL): A lubrication regime combining elastic deformation of surfaces and hydrodynamic pressure effects under high contact stress.

Superlubricity: A state of near-zero friction achieved through incommensurate or self-lubricating contacts at nanoscale interfaces.

Hydration lubrication: A mechanism where structured layers of water around charged groups act as nanometre-thin lubricating films in aqueous environments.

References

1. Design and optimization of fluid lubricated bearings operated with extreme working performances—a comprehensive review. International Journal of Extreme Manufacturing (2024).
2. Influence of tribology on global energy consumption, costs and emissions. Friction (2017).
3. Robust microscale superlubricity under high contact pressure enabled by graphene-coated microsphere. Nature Communications (2017).
4. Origins of hydration lubrication. Nature Communications (2015).
5. A review of recent advances in tribology. Friction (2020).