TY - JOUR
T1 - Mode Coupling in Dynamic Atomic Force Microscopy
AU - Chandrashekar, Abhilash
AU - Belardinelli, Pierpaolo
AU - Lenci, Stefano
AU - Staufer, Urs
AU - Alijani, Farbod
PY - 2021
Y1 - 2021
N2 - Increasing the signal-to-noise ratio in dynamic atomic force microscopy plays a key role in nanomechanical mapping of materials with atomic resolution. In this work, we develop an experimental procedure for increasing the sensitivity of higher harmonics of an atomic-force-microscope cantilever without modifying the cantilever geometry but instead by utilizing dynamical mode coupling between its flexural modes of vibration. We perform experiments on different cantilevers and samples and observe that via nonlinear resonance frequency tuning we can obtain a frequency range where strong modal interactions lead to 7-fold and 16-fold increases in the sensitivity of the 6th and 17th harmonics while reducing sample indentation. We derive a numerical model that captures the observed physics and confirms that nonlinear mode coupling is the reason for the increase of the amplitude of higher harmonics during tip-sample interactions.
AB - Increasing the signal-to-noise ratio in dynamic atomic force microscopy plays a key role in nanomechanical mapping of materials with atomic resolution. In this work, we develop an experimental procedure for increasing the sensitivity of higher harmonics of an atomic-force-microscope cantilever without modifying the cantilever geometry but instead by utilizing dynamical mode coupling between its flexural modes of vibration. We perform experiments on different cantilevers and samples and observe that via nonlinear resonance frequency tuning we can obtain a frequency range where strong modal interactions lead to 7-fold and 16-fold increases in the sensitivity of the 6th and 17th harmonics while reducing sample indentation. We derive a numerical model that captures the observed physics and confirms that nonlinear mode coupling is the reason for the increase of the amplitude of higher harmonics during tip-sample interactions.
UR - http://www.scopus.com/inward/record.url?scp=85100885521&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.15.024013
DO - 10.1103/PhysRevApplied.15.024013
M3 - Article
AN - SCOPUS:85100885521
VL - 15
JO - Physical Review Applied
JF - Physical Review Applied
SN - 2331-7019
IS - 2
M1 - 024013
ER -