Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

We introduce drive-amplitude-modulation atomic force microscopy as a dynamic mode with outstanding performance in all environments from vacuum to liquids. As with frequency modulation, the new mode follows a feedback scheme with two nested loops: The first keeps the cantilever oscillation amplitude constant by regulating the driving force, and the second uses the driving force as the feedback variable for topography. Additionally, a phase-locked loop can be used as a parallel feedback allowing separation of the conservative and nonconservative interactions. We describe the basis of this mode and present some examples of its performance in three different environments. Drive-amplutide modulation is a very stable, intuitive and easy to use mode that is free of the feedback instability associated with the noncontact-to-contact transition that occurs in the frequency-modulation mode.

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Synergy of Resonant Oscillatory Modes in Atomic Force Microscopy of Polymers

MRS Advances ◽

10.1557/adv.2016.364 ◽

2016 ◽

Vol 1 (25) ◽

pp. 1853-1858 ◽

Cited By ~ 1

Author(s):

Sergei Magonov ◽

Sergey Belikov ◽

John Alexander ◽

Marko Surtchev

Keyword(s):

Atomic Force Microscopy ◽

Amplitude Modulation ◽

Frequency Modulation ◽

Phase Imaging ◽

Force Microscopy ◽

Atomic Force ◽

Heterogeneous Samples ◽

Modulation Mode

ABSTRACTThe set of oscillatory resonance AFM modes is expanded with frequency modulation mode and frequency imaging in amplitude modulation mode. The backgrounds of these modes are discussed and their capabilities are compared on the practical examples. The data show how these techniques complement the amplitude modulation with phase imaging. The frequency imaging enhances the compositional mapping of heterogeneous samples. Frequency modulation mode provides a superior capability in imaging at low tip-sample forces.

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Microstructure and roughness of photopolymerized poly(ethylene glycol) diacrylate hydrogel as measured by atomic force microscopy in amplitude and frequency modulation mode

Applied Surface Science ◽

10.1016/j.apsusc.2013.04.089 ◽

2013 ◽

Vol 279 ◽

pp. 300-309 ◽

Cited By ~ 16

Author(s):

M. Munz

Keyword(s):

Atomic Force Microscopy ◽

Ethylene Glycol ◽

Frequency Modulation ◽

Poly Ethylene Glycol ◽

Glycol Diacrylate ◽

Force Microscopy ◽

Atomic Force ◽

Modulation Mode ◽

Poly Ethylene ◽

Amplitude And Frequency Modulation

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Probing the Adsorption of Weak Acids on Graphite Using Amplitude Modulation–Frequency Modulation Atomic Force Microscopy

Langmuir ◽

10.1021/la5048968 ◽

2015 ◽

Vol 31 (10) ◽

pp. 3069-3075 ◽

Cited By ~ 5

Author(s):

Ahmed M. A. Moustafa ◽

Jun Huang ◽

Kerry N. McPhedran ◽

Hongbo Zeng ◽

Mohamed Gamal El-Din

Keyword(s):

Atomic Force Microscopy ◽

Amplitude Modulation ◽

Frequency Modulation ◽

Modulation Frequency ◽

Weak Acids ◽

Force Microscopy ◽

Atomic Force

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Analysis of force-deconvolution methods in frequency-modulation atomic force microscopy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.3.27 ◽

2012 ◽

Vol 3 ◽

pp. 238-248 ◽

Cited By ~ 22

Author(s):

Joachim Welker ◽

Esther Illek ◽

Franz J Giessibl

Keyword(s):

Atomic Force Microscopy ◽

Frequency Shift ◽

Frequency Modulation ◽

Matrix Method ◽

Oscillation Amplitude ◽

Decay Length ◽

Amplitude Dependence ◽

Force Microscopy ◽

Atomic Force ◽

The Matrix

In frequency-modulation atomic force microscopy the direct observable is the frequency shift of an oscillating cantilever in a force field. This frequency shift is not a direct measure of the actual force, and thus, to obtain the force, deconvolution methods are necessary. Two prominent methods proposed by Sader and Jarvis (Sader–Jarvis method) and Giessibl (matrix method) are investigated with respect to the deconvolution quality. Both methods show a nontrivial dependence of the deconvolution quality on the oscillation amplitude. The matrix method exhibits spikelike features originating from a numerical artifact. By interpolation of the data, the spikelike features can be circumvented. The Sader–Jarvis method has a continuous amplitude dependence showing two minima and one maximum, which is an inherent property of the deconvolution algorithm. The optimal deconvolution depends on the ratio of the amplitude and the characteristic decay length of the force for the Sader–Jarvis method. However, the matrix method generally provides the higher deconvolution quality.

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Bimodal atomic force microscopy driving the higher eigenmode in frequency-modulation mode: Implementation, advantages, disadvantages and comparison to the open-loop case

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.4.20 ◽

2013 ◽

Vol 4 ◽

pp. 198-207 ◽

Cited By ~ 27

Author(s):

Daniel Ebeling ◽

Santiago D Solares

Keyword(s):

Atomic Force Microscopy ◽

Frequency Modulation ◽

Operation Mode ◽

Excitation Amplitude ◽

Open Loop ◽

Constant Frequency ◽

Force Microscopy ◽

Advantages And Disadvantages ◽

Atomic Force ◽

Modulation Mode

We present an overview of the bimodal amplitude–frequency-modulation (AM-FM) imaging mode of atomic force microscopy (AFM), whereby the fundamental eigenmode is driven by using the amplitude-modulation technique (AM-AFM) while a higher eigenmode is driven by using either the constant-excitation or the constant-amplitude variant of the frequency-modulation (FM-AFM) technique. We also offer a comparison to the original bimodal AFM method, in which the higher eigenmode is driven with constant frequency and constant excitation amplitude. General as well as particular characteristics of the different driving schemes are highlighted from theoretical and experimental points of view, revealing the advantages and disadvantages of each. This study provides information and guidelines that can be useful in selecting the most appropriate operation mode to characterize different samples in the most efficient and reliable way.

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Subnanometer-scale imaging of nanobio-interfaces by frequency modulation atomic force microscopy

Biochemical Society Transactions ◽

10.1042/bst20200155 ◽

2020 ◽

Vol 48 (4) ◽

pp. 1675-1682

Author(s):

Takeshi Fukuma

Keyword(s):

Atomic Force Microscopy ◽

Frequency Modulation ◽

Critical Role ◽

Surface Structures ◽

Scale Model ◽

Dynamic Mode ◽

Biological Applications ◽

Scanning Method ◽

Force Microscopy ◽

Atomic Force

Recently, there have been significant advancements in dynamic-mode atomic force microscopy (AFM) for biological applications. With frequency modulation AFM (FM-AFM), subnanometer-scale surface structures of biomolecules such as secondary structures of proteins, phosphate groups of DNAs, and lipid-ion complexes have been directly visualized. In addition, three-dimensional AFM (3D-AFM) has been developed by combining a high-resolution AFM technique with a 3D tip scanning method. This method enabled visualization of 3D distributions of water (i.e. hydration structures) with subnanometer-scale resolution on various biological molecules such as lipids, proteins, and DNAs. Furthermore, 3D-AFM also allows visualization of subnanometer-scale 3D distributions of flexible surface structures such as thermally fluctuating lipid headgroups. Such a direct local information at nano-bio interfaces can play a critical role in determining the atomic- or molecular-scale model to explain interfacial structures and functions. Here, we present an overview of these recent advancements in the dynamic-mode AFM techniques and their biological applications.

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Visualization of molecular binding sites at the nanoscale in the lift-up mode by amplitude-modulation atomic force microscopy

Nanoscale ◽

10.1039/d0nr06125e ◽

2021 ◽

Vol 13 (7) ◽

pp. 4213-4220

Author(s):

Tatsuhiro Maekawa ◽

Takashi Nyu ◽

Evan Angelo Quimada Mondarte ◽

Hiroyuki Tahara ◽

Kasinan Suthiwanich ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Molecular Recognition ◽

Amplitude Modulation ◽

Binding Sites ◽

Local Distribution ◽

New Approach ◽

Molecular Binding ◽

Force Microscopy ◽

Atomic Force ◽

Recognition Sites

We report a new approach to visualize the local distribution of molecular recognition sites with nanoscale resolution by amplitude-modulation atomic force microscopy.

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