Atomic force microscope studies of stainless steel: Surface morphology andcolloidal particle adhesion

An atomic force microscope has been used to image four commercial stainless steel samples of widely differing surface finishes. Analysis of the images allowed quantification of surface roughness over different area scales, 50 x 50 mum, 10 x 10 mum and 1 x 1 mum. The atomic force microscope was also used to measure directly the adhesion of a single polymer latex particle (r adius similar to5 mum) to the surface in solution using the colloid probe t echnique. It was found that the adhesion increased with decreasing roughnes s, except for the smoothest surface which exhibited very regular surface fe atures on the area scale most relevant to adhesion of the particle (1 x 1 m um). There was a good correlation between the variability of adhesion over each surface and the corresponding variability in surface roughness. Measur ements of this type should prove useful in the technical/economic choice of surface finish for a particular purpose. As the colloid probe has dimensio ns comparable to those of bacteria and yeast cells, such measurements shoul d especially be of value in the selection of surface finish likely to minim ise bioadhesion. (C) 2001 Kluwer Academic Publishers.