Use of the Atomic Force Microscope to Study Mechanical Properties of Lubricant Layers

MRS Bulletin ◽  
1993 ◽  
Vol 18 (5) ◽  
pp. 20-25 ◽  
Author(s):  
Miquel B. Salmeron
Keyword(s):  
Atomic Force Microscope ◽  
Surface Force ◽  
Separation Distance ◽  
Atomic Scale ◽  
Simple Estimate ◽  
Flat Surfaces ◽  
Atomic Force ◽  
Length Increase ◽  
Order Of Magnitude ◽  
Atomically Flat

Advances in our understanding of the phenomena of adhesion, friction, and lubrication are facilitated by the recent development of new tools that allow the study of contacts in close-to-ideal conditions. These new tools are the surface force spparatus (SFA) and the atomic force microscope (AFM). The first was developed by Israelachvili in the 1970s. In this device, contact between two atomically flat surfaces of mica occurs over an area of several micrometers in diameter after the mica sheets, glued onto two perpendicular cylindrical lenses, are compressed. Force, area of contact, and separation distance can be controlled at the atomic scale. The second device, the AFM, was developed by Binnig et al. in 1986. The sharp tip of the AFM is a convenient idealization of a single asperity. In addition, the AFM can be used to image the surface in the weak repulsive or in the attractive modes so that minimum perturbation is introduced by the imaging process itself. These two devices have the necessary sensitivity to allow the application of forces weak enough not to dislodge atoms from their sites during contact. The order of magnitude of the force that can lead to the rupture of chemical bonds is a convenient figure to keep in mind in this context. A simple estimate of this force is obtained by considering a bond-length increase of 1 Å as leading to dissociation. For a bond energy of ≈1 eV, Fb ≈ 1 eV/1 Å ≈ 1 × 10−9 N.

Heat Transfer Spectroscopy and “Heat Transfer-Distance” Curves

2008 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Sheng Shen ◽  
Gang Chen
Keyword(s):  
Heat Transfer ◽  
Radiative Transfer ◽  
Atomic Force Microscope ◽  
Near Field ◽  
Surface Force ◽  
Casimir Forces ◽  
Distance Curve ◽  
Transfer Distance ◽  
Atomic Force ◽  
Order Of Magnitude

Thermal radiative transfer between objects as well as near-field forces such as van der Waals or Casimir forces have their origins in the fluctuations of the electrodynamic field. Near-field radiative transfer between two objects can be enhanced by a few order of magnitude compared to the far-field radiative transfer that can be described by Planck’s theory of blackbody radiation and Kirchoff’s laws. Despite this common origin, experimental techniques of measuring near-field forces (using the surface force apparatus and the atomic force microscope) are more sophisticated than techniques of measuring near-field radiative transfer. In this work, we present an ultra-sensitive experimental technique of measuring near-field using a bi-material atomic force microscope cantilever as the thermal sensor. Just as measurements of near-field forces results in a “force distance curve”, measurement of near-field radiative transfer results in a “heat transfer-distance” curve. Results from the measurement of near-field radiative transfer will be presented.

When Does Continuum Theory Describe Mechanical Contacts?

2005 ◽  
Author(s):  
Binquan Luan ◽  
Mark Robbins
Keyword(s):  
Contact Mechanics ◽  
Amorphous Material ◽  
Continuum Theory ◽  
Atomic Scale ◽  
Curved Surface ◽  
Atomic Force ◽  
Simple Geometry ◽  
Contact Width ◽  
Order Of Magnitude ◽  
Atomically Flat

The area of molecular contact between surfaces plays a central role in friction and adhesion. Traditionally it is calculated using continuum contact mechanics, which is known to break down as the contact width approaches atomic dimensions. Yet contact mechanics is being applied at ever smaller lengths, even to atomic force microscope (AFM) tips containing a few atoms. Molecular simulations are used to test the limits of contact mechanics under ideal non-adhesive and adhesive conditions. A simple geometry of sphere-on-flat is considered. One surface is an atomically flat crystal and is deformable. The approximately spherical curved surface is rigid and is produced by bending a crystal, or cutting a crystal or amorphous material. While these methods of producing the curved surface differ only in the amount of atomic-scale roughness, they produce very different behavior in some quantities. The normal stiffness is affected very little, the contact area can be modified by a factor of two, and the friction and lateral stiffness can be modified by an order of magnitude. The implications for AFM experiments are discussed.

Fundamental Measurements of the Friction on an Atomically-Flat Terrace of Au(100) in Sulfuric Acid Solution under Potential Control Using Electrochemical Atomic Force Microscope

2006 ◽  
Vol 512 ◽  
pp. 395-398
Author(s):  
Nobumitsu Hirai ◽  
Tatsuya Tooyama ◽  
Toshihiro Tanaka
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Silicon Nitride ◽  
Acid Solution ◽  
Atomic Force Microscope ◽  
Friction Force ◽  
Potential Range ◽  
Potential Control ◽  
Atomic Force ◽  
Atomically Flat

Potential dependence of the friction force between an atomically-flat terrace of Au(100) single crystal and a tip attached to a silicon nitride cantilever of electrochemical atomic force microscope (EC-AFM) have been investigated qualitatively in 0.05 M H2SO4 aqueous solution. It is found that the friction force gains when the potential increases in the potential range between −400 mV and 400 mV vs Hg/Hg2SO4 electrode.

Modelling atomic scale manipulation with the non-contact atomic force microscope

2006 ◽  
Vol 17 (23) ◽  
pp. 5866-5874 ◽  
Author(s):  
T Trevethan ◽  
M Watkins ◽  
L N Kantorovich ◽  
A L Shluger ◽  
J Polesel-Maris ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Atomic Scale ◽  
Atomic Force

Atomic-scale electric capacitive change detected with a charge amplifier installed in a non-contact atomic force microscope

2016 ◽  
Vol 9 (4) ◽  
pp. 046601 ◽  
Author(s):  
Makoto Nogami ◽  
Akira Sasahara ◽  
Toyoko Arai ◽  
Masahiko Tomitori
Keyword(s):  
Atomic Force Microscope ◽  
Atomic Scale ◽  
Charge Amplifier ◽  
Atomic Force ◽  
A Charge

scholarly journals Atomic Resolution with the Atomic Force Microscope

1995 ◽  
Vol 3 (4) ◽  
pp. 6-7
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Atomic Force Microscopy ◽  
Scanning Tunneling Microscopy ◽  
Atomic Force Microscope ◽  
Recent Article ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force

For biologic studies, atomic force microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM) because it has the capability of imaging non-conducting biologic specimens. However, STM generally gives better resolution than AFM, and we're talking about resolution on the atomic scale. In a recent article, Franz Giessibl (Atomic resolution of the silicon (111)- (7X7) surface by atomic force microscopy, Science 267:68-71, 1995) has demonstrated that atoms can be imaged by AFM.

A comparison of dynamic atomic force microscope set-ups for performing atomic scale manipulation experiments

2007 ◽  
Vol 18 (34) ◽  
pp. 345503 ◽  
Author(s):  
T Trevethan ◽  
M Watkins ◽  
A L Shluger ◽  
J Polesel-Maris ◽  
S Gauthier ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Atomic Scale ◽  
Atomic Force

scholarly journals Nanoscale Measurement of Surface Roughness and the existing Surface Forces of Aluminum by AFM

2011 ◽  
Vol 2 ◽  
pp. 76-79
Author(s):  
Purna B Pun ◽  
Shobha K Lamichhane
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscope ◽  
Thermal Oxidation ◽  
Surface Force ◽  
Surface Forces ◽  
Crystal Defects ◽  
Surface Contamination ◽  
Thermal Agitation ◽  
Atomic Force ◽  
Aluminum Sample

The surface contamination affects Atomic Force Microscope (AFM) performance. Thermal agitation during mapping doping, thermal oxidation, annealing impurities and crystal defects promotes the roughness; various kinds of forces on the surface can be detected by the interaction between tip of cantilever and sample. This interaction not only help us to understand the characteristics and morphology of the sample but also useful to measure the surface force of the aluminum sample too.Key words: Atomic Force Microscope (AFM) performance; Thermal oxidation; Annealing impurities; Crystal defectsThe Himalayan Physics Vol.2, No.2, May, 2011Page: 76-79Uploaded Date: 1 August, 2011

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