Quantitative Measurement of Friction between Single Microspheres by Friction Force Microscopy Xing Ling Hans-Jürgen Butt Michael Kappl 10.1021/la700408v.s004 https://acs.figshare.com/articles/journal_contribution/Quantitative_Measurement_of_Friction_between_Single_Microspheres_by_Friction_Force_Microscopy/2993881 The sliding friction between single silica microspheres was examined by applying friction force microscopy to probe the interaction between spherical silica particles glued to a tipless atomic force microscopy (AFM) cantilever and another particle glued to a glass slide. A three-dimensional model handling the complex contact geometry between spherical particles was established to compute friction and normal forces at the sliding interface from measured deflections of the AFM cantilever. Results obtained at different loads show a linear relationship between friction and normal force, with a friction coefficient of 0.4 between silica spheres. Friction in this system occurs at multi-asperity contacts. The results show that the macroscopic friction law of Amontons can be used to model the friction behavior of micrometer-sized granular matter. For plasma-treated silica particles, increased friction as well as wear could be observed during sliding. 2007-07-31 00:00:00 friction coefficient Friction Force MicroscopyThe silica particles AFM cantilever model handling friction force microscopy results show silica spheres glass slide macroscopic friction law force microscopy Quantitative Measurement loads show silica microspheres friction behavior contact geometry Single Microspheres