Inverted stick-slip friction

Sliding of adhesive boundary lubricated surfaces immersed in aqueous solutions has been studied. Under certain conditions "inverted" stick-slip motion is observed where, in contrast to conventional stick-slip, the friction spikes point down rather than up and the transition from smooth to stick-slip sliding occurs above rather than below some critical driving velocity. For the first time, inverted stick-slip motion has been studied in detail and theoretically analyzed in terms of a general model based on the kinetics of formation and rupture of adhesive links (bonds) between two shearing surfaces.