Theory of menisci and its applications

A theory for liquid menisci formed at an arbitrary interface is developed including surface interactions and liquid evaporation. Its applications to scanning probe techniques and laser textured magnetic disks are also given. The meniscus force is shown to be proportional to meniscus size for none-spherical contacts, but nearly independent for spherical contacts. Stronger surface interactions on the liquid film result in the formation of smaller menisci, whereas a thicker liquid film causes larger menisci. The theory predicts that the meniscus (adhesion) force can be effectively reduced when using the same surface material for the interface that can be wetted by the liquid film. Analytical formulae for meniscus forces are derived for widely encountered spherical/conical tips. Comparisons with existing experiments and macroscopic theories are also discussed. (C) 1997 American Institute of Physics.