Measuring viscous dissipative interactions in dynamic force microscopy

The periodic motion of a harmonic pendulum in an arbitrary force field including viscous damping is studied as it pertains to dynamic force microscopy. It is shown that the damping constant as a function of tip-sample distance and thus the dissipative force can be obtained unambiguously by measuring the driving-force amplitude versus displacement of the force sensor. This methodology provides the basis for quantitative force spectroscopy of dissipative interactions. © Springer-Verlag 2001.