Adhesion of a punch to a thin membrane

The measurement of adhesion involves not only surface properties, but also the mechanical properties of the substrates in contact, in particular energy dissipation near the fracture front. A method to help elucidate the contribution of this dissipation may be to study the adhesion of thin films. We consider the situation where a spherical punch adheres to a thin membrane, thus leading to deformation of the latter. Equations for estimating the energy of adhesion are developed. The analysis leads to a criterion for the adhesion to be stable whilst separating (quasi-statically) punch and membrane. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.