When designing engineered systems, it is important to be able to specify the surface roughness requirements for the functional surfaces. This task is however not simple. In the course, the surface topography of solid surfaces will be presented through roughness parameters and the way to measure them at different scales and its effect on several physical effects such as wettability of surfaces, contacts and adhesion of surfaces. The objective of this course is to be able to identify the relevant surface roughness parameters and the relevant values.