Atomic Force Microscope Measurements of the Hardness and Elasticity of Peritubular and Intertubular Human Dentin

1996 ◽  
Vol 118 (1) ◽  
pp. 133-135 ◽  
Author(s):  
J. H. Kinney ◽  
M. Balooch ◽  
S. J. Marshall ◽  
G. W. Marshall ◽  
T. P. Weihs
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscope ◽  
Depth Sensing ◽  
Atomic Force ◽  
Silicon Cantilever ◽  
Human Dentin ◽  
Spatially Homogeneous ◽  
Calcified Tissues ◽  
20 Nm ◽  
Hardness Values

An atomic force microscope was used to measure the hardness and elasticity of fully-hydrated peritubular and intertubular human dentin. The standard silicon nitride AFM tip and silicon cantilever assembly were replaced with a diamond tip and stainless steel cantilever having significantly higher stiffness. Hardness was measured as the ratio of the applied force to the projected indentation area for indentations with depths from 10–20 nm. The sample stiffness was measured by imaging specimens in a force-modulated mode. Hardness values of 2.3 ± 0.3 GPa and 0.5 ± 0.1 GPa were measured for the peritubular and intertubular dentin, respectively. Stiffness imaging revealed that the elastic modulus of the peritubular dentin was spatially homogeneous; whereas, there was considerable spatial variation in the elasticity of the intertubular dentin. The atomic force microscope can be used to measure the mechanical properties of fully hydrated calcified tissues at the submicron level of spatial resolution, thus augmenting more traditional depth sensing probes.

Investigating hollow corundum microspheres exfoliation of the elastomeric matrix

2019 ◽  
pp. 135-142
Author(s):  
N. V. Shadrinov ◽  
U. V. Evseeva
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscope ◽  
Butadiene Rubber ◽  
Nitrile Butadiene Rubber ◽  
Elastomeric Matrix ◽  
Atomic Force

The results of study of the influence of hollow corundum microspheres HCM-S (5–100 µm) and HCM-L (70–180 µm) on the properties of nitrile butadiene rubber BNKS-18 are presented. The dependence of elastomer resistance to abrasion impact and physic and mechanical properties on the dispersion and concentration of hollow corundum microspheres is shown. The process of hollow corundum microspheres exfoliation of the elastomeric matrix, which largely determines the change of physic and mechanical properties, has been studied by specially developed stretching device compatible with an atomic force microscope. The paper describes microspheres exfoliation which is conventionally divided into 3 stages.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

scholarly journals Characterisation of the Material and Mechanical Properties of Atomic Force Microscope Cantilevers with a Plan-View Trapezoidal Geometry

2019 ◽  
Vol 9 (13) ◽  
pp. 2604 ◽  
Author(s):  
Ashley D. Slattery ◽  
Adam J. Blanch ◽  
Cameron J. Shearer ◽  
Andrew J. Stapleton ◽  
Renee V. Goreham ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscope ◽  
Young’S Modulus ◽  
Correction Factor ◽  
Young's Modulus ◽  
Spring Constant ◽  
Beam Equation ◽  
Euler Beam ◽  
Plan View ◽  
Atomic Force

Cantilever devices have found applications in numerous scientific fields and instruments, including the atomic force microscope (AFM), and as sensors to detect a wide range of chemical and biological species. The mechanical properties, in particular, the spring constant of these devices is crucial when quantifying adhesive forces, material properties of surfaces, and in determining deposited mass for sensing applications. A key component in the spring constant of a cantilever is the plan-view shape. In recent years, the trapezoidal plan-view shape has become available since it offers certain advantages to fast-scanning AFM and can improve sensor performance in fluid environments. Euler beam equations relating cantilever stiffness to the cantilever dimensions and Young’s modulus have been proven useful and are used extensively to model cantilever mechanical behaviour and calibrate the spring constant. In this work, we derive a simple correction factor to the Euler beam equation for a beam-shaped cantilever that is applicable to any cantilever with a trapezoidal plan-view shape. This correction factor is based upon previous analytical work and simplifies the application of the previous researchers formula. A correction factor to the spring constant of an AFM cantilever is also required to calculate the torque produced by the tip when it contacts the sample surface, which is also dependent on the plan-view shape. In this work, we also derive a simple expression for the torque for triangular plan-view shaped cantilevers and show that for the current generation of trapezoidal plan-view shaped AFM cantilevers, this will be a good approximation. We shall apply both these correction factors to determine Young’s modulus for a range of trapezoidal-shaped AFM cantilevers, which are specially designed for fast-scanning. These types of AFM probes are much smaller in size when compared to standard AFM probes. In the process of analysing the mechanical properties of these cantilevers, important insights are also gained into their spring constant calibration and dimensional factors that contribute to the variability in their spring constant.

Effect of Glass Composition on Mechanical Properties of Interfaces Between Alumina and Silicate Glass

1996 ◽  
Vol 458 ◽  
Author(s):  
Andrey V. Zagrebelny ◽  
Erica T. Lilleodden ◽  
C. Barry Carter
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Silicate Glass ◽  
Glass Composition ◽  
Depth Sensing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging ◽  
Force Displacement

ABSTRACTInterfaces between glass and crystalline grains have been examined using a thin-film geometry which allows the use of newly developed experimental methods for micromechanical testing of interfaces. In this approach, continuous films of thicknesses ranging 100–200 nm of anorthite (CaAl2Si2O8), celsian (BaAl2Si2O8), and monticellite (CaMgSiO4) are deposited onto single-crystal Al2O3 (α-structure) surfaces of different crystallographic orientations by pulsed-laser deposition (PLD).Mechanical properties such as hardness, stiffness, and reduced Young's modulus were probed with a newly developed high-resolution depth-sensing indentation instrument. Emphasis has been placed on examining how changes in the glass composition will affect the mechanical properties of the single-crystal Al2O3/silicate-glass interfaces. The indentation data obtained from these experiments correlate directly to the morphology of the deformed regions imaged with atomic force microscopy (AFM). Nanomechanical tests combined with AFM imaging of the deformed regions allow force-displacement measurements and in-situ imaging of the same regions of the specimen before and immediately after indentation. This new technique eliminates the uncertainty of locating the indenter after unloading.

scholarly journals Friction anisotropy: A unique and intrinsic property of decagonal quasicrystals

2008 ◽  
Vol 23 (5) ◽  
pp. 1488-1493 ◽  
Author(s):  
Jeong Young Park ◽  
D.F. Ogletree ◽  
M. Salmeron ◽  
C.J. Jenks ◽  
P.A. Thiel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Oxide Film ◽  
Atomic Force Microscope ◽  
Atomic Structure ◽  
Intrinsic Property ◽  
Friction Anisotropy ◽  
Nanometer Size ◽  
Atomic Force ◽  
Decagonal Quasicrystals ◽  
Pin On Disk

We show that friction anisotropy is an intrinsic property of the atomic structure of Al–Ni–Co decagonal quasicrystals and not only of clean and well-ordered surfaces that can be prepared in vacuum [J.Y. Park et al., Science309, 1354 (2005)]. Friction anisotropy is manifested in both nanometer-size contacts obtained with sharp atomic force microscope tips and macroscopic contacts produced in pin-on-disk tribometers. We show that the friction anisotropy, which is not observed when an amorphous oxide film covers the surface, is recovered when the film is removed due to wear. Equally important is the loss of the friction anisotropy when the quasicrystalline order is destroyed due to cumulative wear. These results reveal the intimate connection between the mechanical properties of these materials and their peculiar atomic structure.

Sign in / Sign up

Export Citation Format

Share Document