New insights into the capillary retention force and the work of adhesion

We calculate the normal capillary retention force that anchors a drop to a solid surface in the direction perpendicular to the surface, and study the relationship between such force and the Young-Dupre work of adhesion. We also calculate the work necessary to create or destroy a patch of solid-liquid interface by moving the triple line on a solid substrate. We argue that when the capillary number is small and a drop is sliding on a surface at constant speed, the lateral retention force is the major source of energy dissipation, whereas viscous dissipation plays a minor role.