Nanoscale surface property estimation using proper orthogonal decomposition in atomic force microscopy

Atomic force microscopy (AFM) in a dynamic mode operation uses a resonating tip to measure the nanoscale surface topography and other properties. The dynamic response of the tip includes the complex tip–surface interactions due to the surface properties. We found that conventional tapping mode had a limitation in the accurate set-point control on soft and high adhesion surfaces. This study employed the proper orthogonal decomposition (POD)-based AFM microcantilever characterization method to estimate the surface property with more reliable control. The POD extracted the dominant empirical modes of the AFM microcantilever during tapping and scanning on the surface. Also the corresponding eigenvalues represented the significance of the empirical modes and the characteristic features of the nanoscale surface property. This experimental approach can offer a new insight on the novel application of nanoscale surface property estimation in dynamic AFM applications.