Parylene coatings, particularly Parylene C and Parylene N, are widely used in micro-mechanical and precision assemblies. Owing to their low surface energy (typically 25–30 mN/m), Parylene films can significantly reduce the coefficient of friction (CoF) between contacting surfaces [1].
Published tribological studies report that, under dry sliding conditions against polished steel, Parylene coatings typically exhibit coefficients of friction between 0.20 and 0.35, depending on the applied load and surface roughness [2,3]. This performance is comparable to that of polytetrafluoroethylene (PTFE), making Parylene particularly suitable for moving components. Unlike certain conventional lubricants, the coating forms a stable, adherent film that does not flake or generate particulate contamination.
[1] K. K. Gleason, CVD Polymers: Fabrication of Organic Surfaces and Devices, Wiley, 2015.
[2] J. R. T. Branco et al., “Tribological behavior of Parylene coatings under dry sliding conditions,” Surface and Coatings Technology, 2006.
[3] Y. K. Kim et al., “Friction and wear characteristics of Parylene C coatings,” Wear, vol. 259, 2005