US Patent 7287419 Method of measuring interfacial adhesion properties of stents

A method for measuring toughness of interfacial adhesion including applying a normal force with a probe to a surface of a coating joined to a major surface of a substrate of a medical stent, wherein the surface is substantially parallel to the major surface, and applying a lateral force to the coating with the probe by laterally moving a position of the probe relative to the major surface such that the probe forms at least one delaminated region in the coating as the position of the probe moves laterally across the major surface, the delaminated region having a starting point and an ending point. The method further includes measuring a magnitude of the lateral force over time, and determining a toughness of interfacial adhesion between the coating and the major surface based on changes in magnitude of the lateral force as the position of the probe moves from the starting point to ending point.