Friction and Adhesion in the Nanoworld

Macroscopic observations have led to a couple of phenomenological friction laws, such as Amontons’ law, the Rouse model, or Stokes’ law. Our atomic force microscopy (AFM) based nanoscale measurements with various single polymers as probes necessitate an additional friction mechanism, which we term desorption stick. We discuss how nanoscale friction is related to normal force, polymer length, velocity and adhesion. In addition, we investigate friction mechanisms for articular cartilage, including lubrication and wear, by a combination of AFM and fluorescence based experiments.