Scanning polarization force microscopy: A technique for imaging liquids and weakly adsorbed layers

Abstract

The atomic force microscope is used to measure dielectric polarization forces on surfaces induced by a charged tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using polarization forces we have been able to image liquid films, droplets, and other weakly adsorbed material.