Friction control in soft materials enabled through local stick−slip motion at contact interface

This paper presents a novel friction control method that introduces internal stiffness inhomogeneity into soft material surfaces that slide on rough surfaces. This approach involves embedding hard particles within a soft material to control friction. When these particles encounter asperities on a rough surface during sliding, they trigger a local stick−slip-like motion that leads to energy dissipation and increased macroscopic friction. The validity of the concept was demonstrated through experiments using a simplified setup with triangular periodic one-dimensional roughness. This method is expected to be useful for designing various soft material sliding surfaces.