Quantification of solvation forces with amplitude modulation AFM.

Area of Science:

• Surface Science
• Materials Science
• Colloid Science

Background:

• Interfacial solvation forces are critical for phenomena in materials science and biology but remain poorly understood at the molecular level.
• Three-dimensional atomic force microscopy (3D AFM) offers atomically resolved imaging of solid-liquid interfaces (SLIs), but converting data to accurate forces is challenging.

Purpose of the Study:

• To compare standard amplitude modulation atomic force microscopy (AM-AFM) force reconstruction methods (FRMs) and identify their limitations.
• To introduce and validate a novel numerical matrix-based FRM for AM-AFM to overcome existing inaccuracies in reconstructing SLI forces.

Main Methods:

• Comparison of standard AM-AFM force reconstruction methods (FRMs).
• Development and validation of a novel numerical matrix-based FRM using simulations and experimental 3D AFM data at the silicon oxide-water SLI.

Main Results:

• The novel matrix-based FRM reconstructs the full SLI interaction at the atomic scale without information loss.
• This method is independent of specific AFM experimental parameters and force functional forms.
• The approach overcomes limitations and inaccuracies of standard FRMs.

Conclusions:

• The developed matrix-based FRM significantly advances the understanding of interfacial properties at SLIs.
• This method unlocks the full spectrum of physical phenomena encoded in tip-sample interactions, impacting colloid science, nanoparticle interactions, and molecular self-assembly.