Lubrication Properties of Surface Texture on PDMS

Surface texture with different parameters was fabricated by the Lithography & Replica Molding technique on the soft material PDMS. The effects of surface texture on lubrication properties from mixed to hydrodynamic lubrication regimes were investigated by using a ball-on-disk tribometer. For PDMS, it was found that the diameter of dimples was one of the major factors which influence friction properties obviously. Compared with untextured sample, the pattern with small dimples (with a diameter of 50 μm) resulted a reduction of friction under mixed lubrication and at a low sliding velocity (0.005 m/s), while the pattern with large dimples (with diameter of 200μm) appeared to increase friction. Textures with high dimple area ratio (from 2.6% to 22.9%) have significances on tribological performance under experimental conditions.