Hi Mems people! I'm studying surface roughness correlated to wettability. I've found difficulties in calculating Wenzel's roughness r and the fraction of solid surface in contact with liquid, in cassie's equation, having a random rough surface,(as with geometrical surfaces I can use Patankar's derivations). Can anyone help me? Also does anyone have an idea how to calculate the height–height and lateral correlation function of random surfaces, using AFM? thanks