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Updated: Jun 25, 2026

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid
Published on: December 20, 2016
Compositional contrast of biological materials in liquids using the momentary excitation of higher eigenmodes in
Xin Xu1, John Melcher, Sudipta Basak
1School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Abstract:
Atomic Force microscope (AFM) cantilevers commonly used for imaging soft biological samples in liquids experience a momentary excitation of the higher eigenmodes at each tap. This transient response is very sensitive to the local sample elasticity under gentle imaging conditions because the higher eigenmode time period is comparable to the tip-sample contact time. By mapping the momentary excitation response, we demonstrate a new scanning probe spectroscopy capable of resolving with high sensitivity the variations in the elasticity of soft biological materials in liquids.
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