Influence of Tip Wear on Atomic Force Acoustic Microscopy Experiments

2004 ◽  
Vol 838 ◽  
Keyword(s):  
Experimental Data ◽  
Contact Mechanics ◽  
Elastic Properties ◽  
Visual Information ◽  
Theoretical Models ◽  
Acoustic Microscopy ◽  
Sem Images ◽  
Atomic Force ◽  
Us Government ◽  
Tip Radius

ABSTRACTTip wear and its corresponding change in geometry is a major impediment for quantifying atomic force acoustic microscopy (AFAM). To better understand the process of tip wear and its influence on AFAM measurements of material elastic properties, we have performed a series of experiments and compared tip geometries calculated from experimental data with direct tip visualization in the scanning electron microscope (SEM). Using a sample with known elastic properties, the tip-sample contact stiffnesses for several different cantilevers were determined. Hertz and Derjaguin-Müller-Toporov (DMT) contact-mechanics models were applied to calculate values of the tip radius R from the experimental data. At the same time, values for R before and after each sequence of AFAM measurements were obtained from SEM images. Both methods showed that the tip radius increased with use. However, values of R calculated with the theoretical models varied indeterminately from those obtained from the SEM images. In addition, in some cases analysis of the AFAM measurements suggested a hemispherical tip, while the corresponding SEM images showed that the end of the tip was flat. We also observed other changes in tip shape, such as an increase in the tip width. By combining theoretical models for contact mechanics with visual information on the tip geometry we hope to better understand contact characteristic in AFM-based systems.Contribution of NIST, an agency of the US government; not subject to copyright.

scholarly journals Atomic force acoustic microscopy methods to determine thin-film elastic properties

2003 ◽  
Vol 94 (4) ◽  
pp. 2347-2354 ◽  
Author(s):  
D. C. Hurley ◽  
K. Shen ◽  
N. M. Jennett ◽  
J. A. Turner
Keyword(s):  
Thin Film ◽  
Elastic Properties ◽  
Acoustic Microscopy ◽  
Atomic Force

Measurements of elastic properties of ultra-thin diamond-like carbon coatings using atomic force acoustic microscopy

2001 ◽  
Vol 392 (1) ◽  
pp. 75-84 ◽  
Author(s):  
S. Amelio ◽  
A.V. Goldade ◽  
U. Rabe ◽  
V. Scherer ◽  
B. Bhushan ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Acoustic Microscopy ◽  
Diamond Like Carbon ◽  
Carbon Coatings ◽  
Atomic Force

Size-Related Plasticity Effects in AFM Silicon Cantilever Tips

2006 ◽  
Vol 924 ◽  
Author(s):  
Malgorzata Kopycinska-Mueller ◽  
Roy H. Geiss ◽  
Donna C. Hurley
Keyword(s):  
Sample Surface ◽  
Acoustic Microscopy ◽  
Static Loads ◽  
Theoretical Yield ◽  
Atomic Force ◽  
Silicon Cantilever ◽  
Afm Cantilever ◽  
The Individual ◽  
Tip Radius ◽  
The Impact

ABSTRACTWe are developing dynamic atomic force microscopy (AFM) techniques to determine nanoscale elastic properties. Atomic force acoustic microscopy (AFAM) makes use of the resonant frequencies of an AFM cantilever while its tip contacts the sample surface at a given static load. Our methods involve nanosized silicon probes with tip radius R ranging from approximately 10 nm to 150 nm. The resulting radius of contact between the tip and the sample is less than 20 nm. However, the contact stress can be greater than a few tens of GPa, exceeding the theoretical yield strength of silicon by a factor of two to four. Our AFAM experiments indicate that, contrary to expectation, tips can sometimes withstand such stresses without fracture. We subjected ten tips to the same sequence of AFAM experiments. Each tip was brought into contact with a fused quartz sample at different static loads. The load was systematically increased from about 0.4 μN to 6 μN. Changes in tip geometry were observed in images acquired in a scanning electron microscope (SEM) between the individual AFAM experiments. All of the tips with R < 10 nm broke during the first AFAM experiments at static loads less than 1.6 μN. Tips with R > 40 nm plastically deformed under such loads. However, a group of tips with R from 25 nm to 30 nm neither broke nor deformed during the tests. In order to reach higher contact stresses, two additional tips with similar values of R were used in identical experiments on nickel and sapphire samples. Although the estimated stresses exceeded 40 GPa, we did not observe any tip fracture events. Our qualitative observations agree with more systematic studies performed by other groups on various nanostructures. The results emphasize the necessity of understanding the mechanics of nanometer-scaled bodies and the impact of size effects on measurements of mechanical properties on such scales.

Effect of Actual Indenter Shape on the Results of Spherical Nanoindentation

2016 ◽  
Vol 368 ◽  
pp. 25-28 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Ondřej Kovářík ◽  
Marek Škereň
Keyword(s):  
3D Reconstruction ◽  
Atomic Force Microscope ◽  
Penetration Depth ◽  
Sem Images ◽  
Atomic Force ◽  
High Penetration ◽  
Actual Shape ◽  
Tip Radius ◽  
Indenter Shape ◽  
Penetration Depths

Actual shape of the diamond spherical indenter of nominal radius 20 μm was investigated in this study. 3D reconstruction was performed by atomic force microscope and by the method of stereopair using SEM images of the tip taken under several different angles. The results were compared with the shape obtained indirectly by the calibration performed on specimens with known Young’s modulus. It was found that lower effective values of tip radius for the small penetration depths are caused by the irregular geometry of contact between indenter and specimen surface. With increasing penetration depth the radius increased to the theoretical values and it decreased again for high penetration depths. The stress-strain curves were determined using corrected effective indenter radius.

Quantitative Evaluation of Elastic Properties of Nano-Crystalline Nickel Using Atomic Force Acoustic Microscopy

2008 ◽  
Vol 222 (2-3) ◽  
pp. 471-498 ◽  
Author(s):  
M. Kopycinska-Müller ◽  
A. Caron ◽  
S. Hirsekorn ◽  
U. Rabe ◽  
Harald Natter ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Quantitative Evaluation ◽  
Acoustic Microscopy ◽  
Atomic Force ◽  
Nano Crystalline

In situ determination of effective tip radius in dynamic atomic force microscopy

2014 ◽  
Vol 1652 ◽  
Author(s):  
C. Maragliano ◽  
A. Glia ◽  
M. Stefancich ◽  
M. Chiesa
Keyword(s):  
Atomic Force Microscopy ◽  
Quantitative Information ◽  
Sem Images ◽  
Reliable Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Capacitance Curve ◽  
Tip Radius

AbstractAtomic force microscopy (AFM) suffers from an important limitation: it does not provide quantitative information about the scanned sample. This is because too many unknowns come into play in AFM measurements. The shape of the tip is probably the most important. A technique able to characterize in situ the shape of the tip apex would represent an important step ahead to turn the AFM into a quantitative tool.Standard methods can be destructive to the tip and are time consuming. Two main methods are currently used to characterize the tip radius in situ without affecting its shape. The first consists of characterizing the tip radius by monitoring the dynamics of the cantilever. The value of free amplitude, for which transitions from the attractive to repulsive force regimes are observed, strongly depends on the curvature of the tip. The second method to characterize the tip radius consists instead on fitting the capacitance curve of the tip-sample system with an analytical function.In this work we compare the two methods to characterize in situ the tip radius and results are verified with SEM images. The value of the free amplitude is correlated with the value of R while the capacitance curve is derived with a method we proposed. Tips with different tip radii are used. The investigation is conducted with the aim of determining the most reliable technique for characterizing the tip radius for both sharp and blunt tips.

scholarly journals An Atomic Force Acoustic Microscopy Image Fusion Method Based on Grayscale Inversion and Selection of Best-Fit Intensity

2020 ◽  
Vol 10 (23) ◽  
pp. 8645
Author(s):  
Zhaozheng Chen ◽  
Xiaoqing Li ◽  
Mingyue Ding
Keyword(s):  
Mutual Information ◽  
Visual Information ◽  
Acoustic Microscopy ◽  
Atomic Force ◽  
Acoustic Images ◽  
Internal Structures ◽  
Microscopy Image ◽  
Information Fidelity ◽  
Best Fit ◽  
Selection Of

Atomic force acoustic microscopy (AFAM) can provide surface morphology and internal structures of the samples simultaneously, with broad potential in non-destructive imaging of cells. As the output of AFAM, morphology and acoustic images reflect different features of the cells, respectively. However, there are few studies about the fusion of these images. In this paper, a novel method is proposed to fuse these two types of images based on grayscale inversion and selection of best-fit intensity. First, grayscale inversion is used to transform the morphology image into a series of inverted images with different average intensities. Then, the max rule is applied to fuse those inverted images and acoustic images, and a group of pre-fused images is obtained. Finally, a selector is employed to extract and export the expected image with the best-fit intensity among those pre-fused images. The expected image can preserve both the acoustic details of the cells and the background’s gradient information well, which benefits the analysis of the cell’s subcellular structure. The experiments’ results demonstrated that our method could provide the clearest boundaries between the cells and background, and preserve most details from the morphology and acoustic images according to quantitative comparisons, including standard deviation, mutual information, Xydeas and Petrovic metric, feature mutual information, and visual information fidelity fusion.

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