scholarly journals Nanoscale effects in the characterization of viscoelastic materials with atomic force microscopy: coupling of a quasi-three-dimensional standard linear solid model with in-plane surface interactions

2016 ◽  
Vol 7 ◽  
pp. 554-571 ◽  
Author(s):  
Santiago D Solares
Keyword(s):  
Atomic Force Microscopy ◽  
Computational Study ◽  
Plane Surface ◽  
Material Behavior ◽  
Dynamic Mode ◽  
Viscoelastic Materials ◽  
Force Microscopy ◽  
Atomic Force ◽  
Standard Linear Solid ◽  
Standard Linear

Significant progress has been accomplished in the development of experimental contact-mode and dynamic-mode atomic force microscopy (AFM) methods designed to measure surface material properties. However, current methods are based on one-dimensional (1D) descriptions of the tip–sample interaction forces, thus neglecting the intricacies involved in the material behavior of complex samples (such as soft viscoelastic materials) as well as the differences in material response between the surface and the bulk. In order to begin to address this gap, a computational study is presented where the sample is simulated using an enhanced version of a recently introduced model that treats the surface as a collection of standard-linear-solid viscoelastic elements. The enhanced model introduces in-plane surface elastic forces that can be approximately related to a two-dimensional (2D) Young’s modulus. Relevant cases are discussed for single- and multifrequency intermittent-contact AFM imaging, with focus on the calculated surface indentation profiles and tip–sample interaction force curves, as well as their implications with regards to experimental interpretation. A variety of phenomena are examined in detail, which highlight the need for further development of more physically accurate sample models that are specifically designed for AFM simulation. A multifrequency AFM simulation tool based on the above sample model is provided as supporting information.

scholarly journals Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

2014 ◽  
Vol 5 ◽  
pp. 1649-1663 ◽  
Author(s):  
Santiago D Solares
Keyword(s):  
Atomic Force Microscopy ◽  
Creep Compliance ◽  
Single Mode ◽  
Solid Model ◽  
Force Microscopy ◽  
Atomic Force ◽  
Standard Linear Solid Model ◽  
Standard Linear Solid ◽  
Standard Linear ◽  
Intermittent Contact

This paper presents computational simulations of single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip–sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip–sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample properties and the AFM observables. The physics of the tip–sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided.

Conducting Polymer nanoComposites (CPC): Nanocharacterisation of layer by layer sprayed PMMA-CNT vapour sensors by Atomic force Microscopy in current Sensing Mode (CS-AFM)

2008 ◽  
Vol 1143 ◽  
Author(s):  
Bijandra Kumar ◽  
Mickaël Castro ◽  
Jianbo Lu ◽  
Jean-François Feller
Keyword(s):  
Atomic Force Microscopy ◽  
Spray Deposition ◽  
Dynamic Mode ◽  
Layer By Layer ◽  
Initial State ◽  
Contact Mode ◽  
Current Sensing ◽  
Multi Wall Carbon Nanotubes ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTOrganic vapour sensors based on poly (methylmethacrylate)-multi-wall carbon nanotubes (PMMA-CNT) conductive polymer nanocomposite (CPC) were developed via layer by layer technique by spray deposition. CPC Sensors were exposed to three different classes of solvents (chloroform, methanol and water) and their chemo-electrical properties were followed as a function of CNTcontent in dynamic mode. Detection time was found to be shorter than that necessary for full recovery of initial state. CNT real three dimensional network has been visualized by Atomic force microscopy in a field assisted intermittent contact mode. More interestingly real conductive network system and electrical ability of CPC have been explored by current-sensing atomic force microscopy (CS-AFM). Realistic effect of voltage on electrical conductivity has been found linear.

Atomic Force Microscopy

2021 ◽  
pp. 379-400
Author(s):  
C. Julian Chen
Keyword(s):  
Atomic Force Microscopy ◽  
Entire Range ◽  
Tunneling Current ◽  
Vibrational Amplitude ◽  
Dynamic Mode ◽  
Dynamic Force ◽  
Force Detection ◽  
Static Mode ◽  
Force Microscopy ◽  
Atomic Force

This chapter discusses atomic force microscopy (AFM), focusing on the methods for atomic force detection. Although the force detection always requires a cantilever, there are two types of modes: the static mode and the dynamic mode. The general design and the typical method of manufacturing of the cantilevers are discussed. Two popular methods of static force detection are presented. The popular dynamic-force detection method, the tapping mode is described, especially the methods in liquids. The non-contact AFM, which has achieved atomic resolution in the weak attractive force regime, is discussed in detail. An elementary and transparent analysis of the principles, including the frequency shift, the second harmonics, and the average tunneling current, is presented. It requires only Newton’s equation and Fourier analysis, and the final results are analyzed over the entire range of vibrational amplitude. The implementation is briefly discussed.

How to measure energy dissipation in dynamic mode atomic force microscopy

1999 ◽  
Vol 140 (3-4) ◽  
pp. 376-382 ◽  
Author(s):  
B. Anczykowski ◽  
B. Gotsmann ◽  
H. Fuchs ◽  
J.P. Cleveland ◽  
V.B. Elings
Keyword(s):  
Atomic Force Microscopy ◽  
Energy Dissipation ◽  
Dynamic Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mode Atomic Force Microscopy

scholarly journals High-speed dynamic-mode atomic force microscopy imaging of polymers: an adaptive multiloop-mode approach

2017 ◽  
Vol 8 ◽  
pp. 1563-1570 ◽  
Author(s):  
Juan Ren ◽  
Qingze Zou
Keyword(s):  
Atomic Force Microscopy ◽  
High Speed ◽  
Interaction Force ◽  
Dynamic Mode ◽  
Microscopy Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Atomic Force Microscopy Imaging ◽  
Mode Tm ◽  
Mode Atomic Force Microscopy

Adaptive multiloop-mode (AMLM) imaging to substantially increase (over an order of magnitude) the speed of tapping-mode (TM) imaging is tested and evaluated through imaging three largely different heterogeneous polymer samples in experiments. It has been demonstrated that AMLM imaging, through the combination of a suite of advanced control techniques, is promising to achieve high-speed dynamic-mode atomic force microscopy imaging. The performance, usability, and robustness of the AMLM in various imaging applications, however, is yet to be assessed. In this work, three benchmark polymer samples, including a PS–LDPE sample, an SBS sample, and a Celgard sample, differing in feature size and stiffness of two orders of magnitude, are imaged using the AMLM technique at high-speeds of 25 Hz and 20 Hz, respectively. The comparison of the images obtained to those obtained by using TM imaging at scan rates of 1 Hz and 2 Hz showed that the quality of the 25 Hz and 20 Hz AMLM imaging is at the same level of that of the 1 Hz TM imaging, while the tip–sample interaction force is substantially smaller than that of the 2 Hz TM imaging.

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

2012 ◽  
Vol 3 ◽  
pp. 336-344 ◽  
Author(s):  
Miriam Jaafar ◽  
David Martínez-Martín ◽  
Mariano Cuenca ◽  
John Melcher ◽  
Arvind Raman ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Amplitude Modulation ◽  
Frequency Modulation ◽  
Driving Force ◽  
Oscillation Amplitude ◽  
Dynamic Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Modulation Mode ◽  
Feedback Scheme

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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