TappingMode™ AFM is an AC technique in which the cantilever is operated at or near its resonance frequency. Forces between tip and sample cause a change of the initial resonance behavior. Typically a reduction in the free air amplitude is maintained to track the sample topography. By simultaneously monitoring the phase shift between drive signal to the cantilever and its response, a so-called phase image can be generated that provides very high spatial information based on various material properties.