A note on the effect of surface topography on adhesion of hard elastic rough bodies with low surface energy

Adhesion between bodies is strongly influenced by surface roughness. In this note, we try to clarify how the statistical properties of the contacting surfaces affect the adhesion under the assumption of long-range adhesive interactions. Specifically, we show that the adhesive interactions are influenced only by the roughness amplitude hrms, while the rms surface gradient h0rmsonly affects the non-Adhesive contact force. This is a remarkable result if one takes into account the intrinsic difficulty in defining h r m s ′ . $h-{mathrm{rms}}^{^{prime }}.$ Results are also corroborated by a comparison with self-consistent numerical calculations.