Dynamics of microcantilever integrated with geometric nonlinearity for stable and broadband nonlinear atomic force microscopy

We explore the use of a nonlinear cantilever system integrating geometric nonlinearity for AFM imaging, in contrast from the traditional linear cantilever system. The intrinsically nonlinear AFM cantilever system exhibits broadband resonance over a bandwidth several times of its linear resonant frequency and possesses an intrinsic stability that virtually eliminates the instability induced by the tip-sample interactions involved in a linear AFM system, thus the artifact of image contrast reversal. The ability to realize broadband operation may extend the application of AFM to spectral analysis of tip-sample interactions across a broad frequency range at the nanoscale.