Wettability and surface forces measured by atomic force microscopy: the role of roughness J. Gavoille, J. Takadoum, N. Martin and D. Durand Eur. Phys. J. Appl. Phys., 48 1 (2009) 10504 Published online: 04 July 2009 DOI: 10.1051/epjap/2009120