Mode Coupling in Dynamic Atomic Force Microscopy

Increasing the signal-to-noise ratio in dynamic atomic force microscopy plays a key role nanomechanical mapping of materials with resolution. In this work, we develop an experimental procedure for increasing sensitivity higher harmonics atomic-force-microscope cantilever without modifying geometry but instead by utilizing dynamical mode coupling between its flexural modes vibration. We perform experiments on different cantilevers and samples observe that via nonlinear resonance frequency tuning can obtain range where strong modal interactions lead to 7-fold 16-fold increases 6th 17th while reducing sample indentation. derive numerical model captures observed physics confirms is reason increase amplitude during tip-sample interactions.