scholarly journals Application of Electrochemical Atomic Force Microscopy (EC-AFM) in the Corrosion Study of Metallic Materials

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 668 ◽  
Author(s):  
Hanbing Chen ◽  
Zhenbo Qin ◽  
Meifeng He ◽  
Yichun Liu ◽  
Zhong Wu
Keyword(s):  
Atomic Force Microscopy ◽  
Early Stage ◽  
Sample Surface ◽  
Electrolytic Cell ◽  
Research Progress ◽  
Force Microscopy ◽  
Research Areas ◽  
Atomic Force ◽  
Wide Range ◽  
Corrosion Science

Electrochemical atomic force microscopy (EC-AFM), a branch of a scanning probe microscopy (SPM), can image substrate topography with high resolution. Since its inception, it was extended to a wide range of research areas through continuous improvement. The presence of an electrolytic cell and a potentiostat makes it possible to observe the topographical changes of the sample surface in real time. EC-AFM is used in in situ corrosion research because the samples are not required to be electrically conductive. It is widely used in passive film properties, surface dissolution, early-stage corrosion initiation, inhibitor efficiency, and many other branches of corrosion science. This review provides the research progress of EC-AFM and summarizes the extensive applications and investigations using EC-AFM in corrosion science.

Atomic force microscopy cantilever simulation by finite element methods for quantitative atomic force acoustic microscopy measurements

2006 ◽  
Vol 21 (12) ◽  
pp. 3072-3079 ◽  
Author(s):  
F.J. Espinoza Beltrán ◽  
J. Muñoz-Saldaña ◽  
D. Torres-Torres ◽  
R. Torres-Martínez ◽  
G.A. Schneider
Keyword(s):  
Atomic Force Microscopy ◽  
Finite Element ◽  
Elastic Modulus ◽  
Finite Element Methods ◽  
Sample Surface ◽  
Acoustic Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Wide Range

Measurements of vibrational spectra of atomic force microscopy (AFM) microprobes in contact with a sample allow a good correlation between resonance frequencies shifts and the effective elastic modulus of the tip-sample system. In this work we use finite element methods for modeling the AFM microprobe vibration considering actual features of the cantilever geometry. This allowed us to predict the behavior of the cantilevers in contact with any sample for a wide range of effective tip-sample stiffness. Experimental spectra for glass and chromium were well reproduced for the numerical model, and stiffness values were obtained. We present a method to correlate the experimental resonance spectrum to the effective stiffness using realistic geometry of the cantilever to numerically model the vibration of the cantilever in contact with a sample surface. Thus, supported in a reliable finite element method (FEM) model, atomic force acoustic microscopy can be a quantitative technique for elastic-modulus measurements. Considering the possibility of tip-apex wear during atomic force acoustic microscopy measurements, it is necessary to perform a calibration procedure to obtain the tip-sample contact areas before and after each measurement.

scholarly journals Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

2016 ◽  
Vol 108 (24) ◽  
pp. 243101 ◽  
Author(s):  
Aymeric Vecchiola ◽  
Pascal Chrétien ◽  
Sophie Delprat ◽  
Karim Bouzehouane ◽  
Olivier Schneegans ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Local Resistance ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Intermittent Contact

scholarly journals Atomic Force Microscopy on Biological Materials Related to Pathological Conditions

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-25 ◽  
Author(s):  
Andreas Stylianou ◽  
Stylianos-Vasileios Kontomaris ◽  
Colin Grant ◽  
Eleni Alexandratou
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Surface Characterization ◽  
Amyloid Fibrils ◽  
Biological Materials ◽  
Force Microscopy ◽  
Fibrous Protein ◽  
Atomic Force ◽  
Pathological Conditions ◽  
Wide Range

Atomic force microscopy (AFM) is an easy-to-use, powerful, high-resolution microscope that allows the user to image any surface and under any aqueous condition. AFM has been used in the investigation of the structural and mechanical properties of a wide range of biological matters including biomolecules, biomaterials, cells, and tissues. It provides the capacity to acquire high-resolution images of biosamples at the nanoscale and allows at readily carrying out mechanical characterization. The capacity of AFM to image and interact with surfaces, under physiologically relevant conditions, is of great importance for realistic and accurate medical and pharmaceutical applications. The aim of this paper is to review recent trends of the use of AFM on biological materials related to health and sickness. First, we present AFM components and its different imaging modes and we continue with combined imaging and coupled AFM systems. Then, we discuss the use of AFM to nanocharacterize collagen, the major fibrous protein of the human body, which has been correlated with many pathological conditions. In the next section, AFM nanolevel surface characterization as a tool to detect possible pathological conditions such as osteoarthritis and cancer is presented. Finally, we demonstrate the use of AFM for studying other pathological conditions, such as Alzheimer’s disease and human immunodeficiency virus (HIV), through the investigation of amyloid fibrils and viruses, respectively. Consequently, AFM stands out as the ideal research instrument for exploring the detection of pathological conditions even at very early stages, making it very attractive in the area of bio- and nanomedicine.

scholarly journals Array atomic force microscopy for real-time multiparametric analysis

2019 ◽  
Vol 116 (13) ◽  
pp. 5872-5877 ◽  
Author(s):  
Qingqing Yang ◽  
Qian Ma ◽  
Kate M. Herum ◽  
Chonghe Wang ◽  
Nirav Patel ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Structure Function ◽  
Function Analysis ◽  
Atomic Scale ◽  
Beam Deflection ◽  
Emergent Properties ◽  
Multiscale Approach ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range

Nanoscale multipoint structure–function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure–function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe–sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks.

Sufficient condition for reliability measurement of sample geometry by atomic force microscopy

2020 ◽  
pp. 11-15
Author(s):  
Alexander S. Kravchuk ◽  
Anzhelika I. Kravchuk
Keyword(s):  
Atomic Force Microscopy ◽  
Preliminary Investigation ◽  
Sample Surface ◽  
Sufficient Condition ◽  
Surface Geometry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Geometric Deviations ◽  
Reliability Measurement ◽  
Microscope Stage

A sufficient condition for determining the reliability of geometry measurements using atomic force microscopy for relatively small cantilever tilt angles is proposed. A relationship between the basic geometric parameters of surface roughness, geometric deviations of the probe, the angles of the cantilever and the inclination of the side faces of the probe, as well as the dimensions of the nonlocal point of the probable contact of its side faces with protrusions of roughness has been established. As a sufficient condition for the reliability of geometry measurements using atomic force microscopy, an obvious requirement is accepted. It determines the smallness of the ratio of the sizes of a nonlocal point to the distance between neighboring nonlocal points. Publications in which the measurement of surface nano-geometry of the samples does not indicate the roughness of the sample surface and the probe, the angles at the tip of the probe and the tilt of the cantilever, as well as the best resolution (smallest step) at which the study is carried out, cannot be accepted as reliable, because the results obtained in them are probabilistic in nature. The surface images obtained using atomic force microscopy without proper justification for the resolution (value of the measurement step) represent only a qualitative picture, on the basis of which it makes no sense to carry out any computational manipulations. In order to increase the reliability of measurements of surface geometry using atomic force microscopy, it is necessary to radically increase the accuracy of the manufacture of probes, as well as use probes with the smallest possible angle at the apex. In addition, it is necessary to make changes in the design of the atomic force microscopy. In particular, the automatic rotation of the microscope stage should be designed. It should provide closeness the probe axis direction to the normal to the average plane of the sample. This “integral” angle of rotation of the microscope stage is easily iteratively determined at the stage of preliminary investigation of the geometry of the surface of the sample. In this case, it will be necessary to geometrically increase the length of the cantilever so that the base extends beyond the limits of the sample.

Features of the Manufacturing Process of Silicon Tips for Cantilevers

2021 ◽  
Vol 26 (3-4) ◽  
pp. 234-245
Author(s):  
A.V. Novak ◽  
◽  
V.R. Novak ◽  
A.V. Rumyantsev ◽  
◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Silicon Film ◽  
Statistical Parameter ◽  
Sample Surface ◽  
Test Sample ◽  
Oxygen Atmosphere ◽  
Maximum Height ◽  
Force Microscopy ◽  
Atomic Force ◽  
Crystallographic Planes

Sample surface examination in atomic force microscopy is carried out using cantilevers having the form of elastic consoles with sharp needle (tip) at the free end. Quality of images obtained from atomic force microscope (AFM) heavily depends on tip sharpness degree. Silicon cantilevers made based on wet anisotropic etching are widely used in atomic force microscopy. This paper studies the dependence of the shape and size of the resulting tip on the concentration of KOH in the solution, as well as the effect of pyrogenic oxidation and oxidation in a dry oxygen atmosphere on the sharpness of the tip during the sharpening process. It was shown that when 70 % concentration is used, tips with the highest aspect ratio and maximum height are obtained. In this case, the shape of the needle is an octagonal pyramid, the lateral faces of which are formed by eight crystallographic planes from {311} and {131}. It was found that in a two-stage sharpening process, consisting of pyrogenic oxidation and oxidation in a dry oxygen atmosphere, it is possible to form sufficiently sharp probes with a tip radius of 2–5 nm and an apex angle of 14–24°. It has been established that a one-stage sharpening process based on pyrogenic oxidation provides only the production of probes with a radius of about 14 nm. Comparative tests of the manufactured probes in obtaining AFM images of a test sample of a polycrystalline silicon film with hemispherical grains (HSG-Si) were presented. Research study has revealed that such a statistical parameter as the relative increment of the surface area Sdr is the most sensitive to probe sharpness for surfaces of the HSG-Si film type.

Investigation of Epitaxial GaN Films by Conductive Atomic Force Microscopy

2003 ◽  
Vol 764 ◽  
Author(s):  
S. Dogan ◽  
J. Spradlin ◽  
J. Xie ◽  
A. A. Pomarico ◽  
R. Cingolani ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Sample Surface ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Topological Features ◽  
Atomic Force ◽  
Local Current ◽  
Semiconductor Junction ◽  
Surrounding Areas ◽  
Conduction Properties

AbstractThe current conduction in GaN is very topical and is the topic of a vast amount of research. By simultaneously mapping the topography and the current distribution, conductive atomic force microscopy (C-AFM) has the potential to establish a correlation between topological features and localized current paths. In this study, this technique was applied to image the conduction properties of as-grown and post-growth chemically etched samples GaN epitaxial layers on a microscopic scale. Our results show that prismatic planes have a significantly higher conductivity than the surrounding areas of the sample surface. A large and stable local current was mainly observed from the walls of the etched pits, under forward and reverse bias of the metallized AFM tip/semiconductor junction.

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