Friction at nanopillared polymer surfaces beyond Amontons’ laws: Stick-slip amplitude coefficient (SSAC) and multiparametric nanotribological properties

Frictional and nanomechanical properties of nanostructured polymer surfaces are important to their technological biomedical applications. In this work, poly(ethylene terephthalate) (PET) with a periodic distribution well-defined nanopillars were fabricated through an anodization/embossing process. The apparent surface energy the nanopillared was evaluated using Fowkes acid-base approach, morphology characterized scanning electron microscope (SEM) atomic force (AFM). normal lateral forces between silica microparticle these quantified colloidal probe microscopy (CP-AFM). friction-load relationship followed Amonton’s first law, friction coefficient appeared scale linearly nanopillar height. Furthermore, all showed pronounced frictional instabilities compared smooth sliding loop on flat control. Performing stick–slip amplitude (SSAC) analysis, we found correlation density, pull-off work adhesion. We have summarised dependence nanotribological such five relevant parameters, i.e. fp, Amontons’ μ, RMS roughness Rq, SSAC, adhesion substrate water Wadh in radar chart. Whilst demonstrating complexity behaviour surfaces, our results show that analyses multiparametric should go beyond classic laws, SSAC more representative coefficient.