Variations on the work and the normal force of adhesion.

The work of adhesion is the amount of work needed to detach a drop from a solid surface, whereas the normal force of adhesion is the force needed to detach a drop from a surface in the direction perpendicular to the surface. In this talk, we will review competing theoretical descriptions of the normal force of adhesion, as well as their connection with the work of adhesion. We will also present a new analysis of some experiments that measured those quantities.