High-Speed Integral Off-Resonance Atomic Force Microscope.

Simultaneous mechanical mapping and high-resolution topographical characterization yield rich compositional information for materials and biomaterials. The off-resonance tapping (ORT) mode in atomic force microscopy (AFM) offers an effective means to achieve this dual functionality. Nevertheless, ORT mode suffers from substantial closed-loop delay and limited robustness, leading to low imaging speeds that hinder its application in studying dynamic specimens. To address these limitations, we developed an integral off-resonance tapping (I-ORT) mode that replaces conventional fixed-point sampling with integral sampling of the interaction curve above the baseline. This method mitigates unpredictable interference from probe-sample interactions while maintaining the same drive and sensing conditions. As a result, I-ORT increases the ORT scanning speed by at least 10-fold without compromising mechanical property characterization. This advancement provides enhanced support for high-end nanotechnological research.