Analysis on the Contact Mechanics between Tip and Sample in Atomic Force Acoustic Microscope Method

2013 ◽  
Vol 800 ◽  
pp. 325-329
Author(s):  
Gai Mei Zhang ◽  
Li Ping Yang ◽  
Chen Qiang ◽  
Yuan Wei ◽  
Jian Dong Lu ◽  
...  
Keyword(s):  
Contact Stiffness ◽  
Sample Surface ◽  
Acoustic Microscopy ◽  
Contact Model ◽  
Contact Theory ◽  
Ultrasonic Technique ◽  
Contact Mode ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Afm Probe

Atomic force acoustic microscopy (AFAM) is a technique combining the atomic force microscope (AFM) and ultrasonic technique, where the cantilever or the sample surface is vibrated at ultrasonic frequencies while a sample surface is scanned with the sensor tip contacting the sample. At a consequence, the amplitude of the cantilever vibration as well as the shift of the cantilever resonance frequencies contain information about local tip-sample contact stiffness and can be used as imaging quantities. It has been demonstrated to be a powerful tool for the investigation of the local elastic prosperities of sample surface. The sample is tested in the contact mode, the resonant frequency of the cantilever is measured, by which the contact stiffness is calculated based on the model of vibration of the cantilever, and then the elastic property of sample is evaluated according to the contact theory. Therefore, the contact model has an important impact on the calculation of elastic modulus. This paper analyzes the contact model between the AFM probe and the sample, and it is investigated based on finite element method (FEM) that the results of the test are affected by parameters.

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.

Quantitative Contact Spectroscopy and Imaging by Atomic-Force Acoustic Microscopy

1999 ◽  
Vol 591 ◽  
Author(s):  
W. Arnold ◽  
S. Amelio ◽  
S. Hirsekorn ◽  
U. Rabe
Keyword(s):  
Young’S Modulus ◽  
Lead Zirconate Titanate ◽  
Young's Modulus ◽  
Contact Stiffness ◽  
Near Field ◽  
Lead Zirconate ◽  
Acoustic Microscopy ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Nanocrystalline Ferrite

ABSTRACTAtomic Force Acoustic Microscopy is a near-field technique which combines the ability in using ultrasonics to image elastic properties with the high lateral resolution of scanning probe microscopes. We present a technique to measure the contact stiffness and the Young's modulus of sample surfaces quantitatively with a resolution of approximately 20 rum exploiting the contact resonance frequencies of standard cantilevers used in Atomic Force Microscopy. The Young's modulus of nanocrystalline ferrite films have been measured as a function of oxidation temperature. Furthermore images showing the domain structure of piezoelectric lead zirconate titanate ceramics have been taken.

Nanoscale Elastic-Property Mapping with Contact-Resonance-Frequency AFM

2004 ◽  
Vol 838 ◽  
Author(s):  
D. C. Hurley ◽  
A. B. Kos ◽  
P. Rice
Keyword(s):  
Resonance Frequency ◽  
Elastic Properties ◽  
Digital Signal Processor ◽  
Contact Stiffness ◽  
Acoustic Microscopy ◽  
Indentation Modulus ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Vertical Contact ◽  
Contact Resonance

ABSTRACTWe describe a dynamic atomic force microscopy (AFM) method to map the nanoscale elastic properties of surfaces, thin films, and nanostructures. Our approach is based on atomic force acoustic microscopy (AFAM) techniques previously used for quantitative measurements of elastic properties at a fixed sample position. AFAM measurements determine the resonant frequencies of an AFM cantilever in contact mode to calculate the tip-sample contact stiffness k*. Local values for elastic properties such as the indentation modulus M can be determined from k* with the appropriate contact-mechanics models. To enable imaging at practical rates, we have developed a frequency-tracking circuit based on digital signal processor architecture to rapidly locate the contact-resonance frequencies at each image position. We present contact-resonance frequency images obtained using both flexural and torsional cantilever images as well as the corresponding vertical contact-stiffness (k*) image calculated from flexural frequency images. Methods to obtain elastic-modulus images of M from vertical contact-stiffness images are also discussed.

scholarly journals Measurement of the Indentation Modulus and the Local Internal Friction in Amorphous SiO2 Using Atomic Force Acoustic Microscopy

2016 ◽  
Vol 61 (1) ◽  
pp. 9-12
Author(s):  
B. Zhang ◽  
H. Wagner ◽  
M. Büchsenschütz-Göbeler ◽  
Y. Luo ◽  
S. Küchemann ◽  
...  
Keyword(s):  
Internal Friction ◽  
Amorphous Materials ◽  
Contact Stiffness ◽  
Ultrasonic Transducer ◽  
Amorphous Material ◽  
Acoustic Microscopy ◽  
Damping Factor ◽  
Indentation Modulus ◽  
Amorphous Sio2 ◽  
Atomic Force

Abstract For the past two decades, atomic force acoustic microscopy (AFAM), an advanced scanning probe microscopy technique, has played a promising role in materials characterization with a good lateral resolution at micro/nano dimensions. AFAM is based on inducing out-of-plane vibrations in the specimen, which are generated by an ultrasonic transducer. The vibrations are sensed by the AFM cantilever when its tip is in contact with the material under test. From the cantilver’s contactresonance spectra, one determines the real and the imaginary part of the contact stiffness k*, and then from these two quantities the local indentation modulus M' and the local damping factor Qloc-1 can be obtained with a spatial resolution of less than 10 nm. Here, we present measured data of M' and of Qloc-1 for the insulating amorphous material, a-SiO2. The amorphous SiO2 layer was prepared on a crystalline Si wafer by means of thermal oxidation. There is a spatial distribution of the indentation modulus M' and of the internal friction Qloc-1. This is a consequence of the potential energy landscape for amorphous materials.

Lorentz Contact Resonance Imaging for Atomic Force Microscopes: Probing Mechanical and Thermal Properties on the Nanoscale

2013 ◽  
Vol 21 (6) ◽  
pp. 18-24 ◽  
Author(s):  
Eoghan Dillon ◽  
Kevin Kjoller ◽  
Craig Prater
Keyword(s):  
Viscoelastic Properties ◽  
Contact Stiffness ◽  
Mechanical And Thermal Properties ◽  
Resonance Modes ◽  
Atomic Force ◽  
Resonance Frequencies ◽  
Other Information ◽  
Afm Cantilever ◽  
Stiffness And Damping ◽  
Contact Resonance

Atomic force microscopy (AFM) has been widely used in both industry and academia for imaging the surface topography of a material with nanoscale resolution. However, often little other information is obtained. Contact resonance AFM (CR-AFM) is a technique that can provide information about the viscoelastic properties of a material in contact with an AFM probe by measuring the contact stiffness between the probe and sample. In CR-AFM, an AFM cantilever is oscillated, and the amplitude and frequency of the resonance modes of the cantilever are monitored. When a probe or sample is oscillated, the tip sample interaction can be approximated as an ideal spring-dashpot system using the Voigt-Kelvin model shown in Figure 1. Contact resonance frequencies of the AFM cantilever will shift depending on the contact stiffness, k, between the tip and sample. The damping effect on the system comes from dissipative tip sample forces such as viscosity and adhesion. Damping, η, is observed in a CR-AFM system by monitoring the amplitude and Q factor of the resonant modes of the cantilever. This contact stiffness and damping information can then be used to obtain information about the viscoelastic properties of the material when fit to an applicable model.

Acquisition of High Precision Images for Non-Contact Atomic Force Microscopy via Direct Identification of Sample Height

2005 ◽  
Author(s):  
H. N. Pishkenari ◽  
Nader Jalili ◽  
A. Meghdari
Keyword(s):  
High Precision ◽  
Single Mode ◽  
Scanning Speed ◽  
Sample Surface ◽  
Biological Species ◽  
Atomic Scale ◽  
Contact Mode ◽  
Practical Applications ◽  
Atomic Force ◽  
Sample Height

Atomic force microscopes (AFM) can image and manipulate sample properties at the atomic scale. The non-contact mode of AFM offers unique advantages over other contemporary scanning probe techniques, especially when utilized for reliable measurements of soft samples (e.g., biological species). The distance between cantilever tip and sample surface is a time varying parameter even for a fixed sample height, and hence, difficult to identify. A remedy to this problem is to directly identify the sample height in order to generate high precision, atomic-resolution images. For this, the microcantilever is modeled by a single mode approximation and the interaction between the sample and cantilever is derived from a van der Waals potential. Since in most practical applications only the microcantilever deflection is accessible, this measurement is utilized to identify the sample height in each point. Using the proposed approach for identification of the sample height, the scanning speed can be increased significantly. Furthermore, for taking atomic-scale images of atomically flat samples, there is no need to use the feedback loop to achieve setpoint amplitude. Simulation results are provided to demonstrate the effectiveness of the approach and suggest the most suitable technique for the sample height identification.

Quantitative determination of contact stiffness using atomic force acoustic microscopy

Ultrasonics ◽  
2000 ◽  
Vol 38 (1-8) ◽  
pp. 430-437 ◽  
Author(s):  
U. Rabe ◽  
S. Amelio ◽  
E. Kester ◽  
V. Scherer ◽  
S. Hirsekorn ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Contact Stiffness ◽  
Acoustic Microscopy ◽  
Atomic Force

The Study of Nanolithography Processing on the Photoresistor Thin Film by Atomic Force Microscopy

2014 ◽  
Vol 997 ◽  
pp. 379-382
Author(s):  
Jen Ching Huang ◽  
Fu Jen Cheng
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Groove Depth ◽  
Cutting Depth ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
On Line ◽  
Afm Probe ◽  
Mode Atomic Force Microscopy

In this paper, the nanomachining experiments on the SPR3001 photoresistor thin films were processing by contact mode atomic force microscopy (AFM). After the experiment, it can be found, in the nanomachining, the greater the indented distance along the Z-axis depth, carved out of the groove depth and groove width of nanoline is greater. The influences of cutting directions on line width and cutting depth during nanomachining were quite a few and the cutting situation was stable by lateral nanomachining. This article also successfully processed the regular hexagonal nanopattern, also proves the nanomachining ability of the AFM probe is good at nanoscale patterned on photoresistor thin films.

scholarly journals A Non-Destructive, Tuneable Method to Isolate Live Cells for High-Speed AFM Analysis

2021 ◽  
Vol 9 (4) ◽  
pp. 680
Author(s):  
Christopher T. Evans ◽  
Sara J. Baldock ◽  
John G. Hardy ◽  
Oliver Payton ◽  
Loren Picco ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
High Speed ◽  
Single Cells ◽  
Sample Surface ◽  
Live Cells ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis

Suitable immobilisation of microorganisms and single cells is key for high-resolution topographical imaging and study of mechanical properties with atomic force microscopy (AFM) under physiologically relevant conditions. Sample preparation techniques must be able to withstand the forces exerted by the Z range-limited cantilever tip, and not negatively affect the sample surface for data acquisition. Here, we describe an inherently flexible methodology, utilising the high-resolution three-dimensional based printing technique of multiphoton polymerisation to rapidly generate bespoke arrays for cellular AFM analysis. As an example, we present data collected from live Emiliania huxleyi cells, unicellular microalgae, imaged by contact mode High-Speed Atomic Force Microscopy (HS-AFM), including one cell that was imaged continuously for over 90 min.

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