Micromechanical Properties of Spruce Tissues Using Static Nanoindentation and Modulus Mapping

2015 ◽  
Vol 732 ◽  
pp. 115-118
Author(s):  
Zdeněk Prošek ◽  
Jaroslav Topič ◽  
Pavel Tesárek ◽  
Kateřina Indrová ◽  
Václav Nežerka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Physical And Mechanical Properties ◽  
Mapping Technique ◽  
Force Microscopy ◽  
Micromechanical Properties ◽  
Atomic Force ◽  
Combination Of Methods ◽  
Dynamic Nanoindentation

This paper discusses characterization of physical and mechanical properties of tissues of Norway spruce. Cell wall is composed of several layers, which is, due to their small size, difficult to characterize. For this reason, the work uses a combination of methods, atomic force microscopy (AFM) and nanoindentation. AFM is used to determine the topography of samples and nanoindentation to determine micromechanical properties of wood tissues. Prepared samples of glue laminated timber were tested by quasi-static and dynamic nanoindentation (modulus mapping technique) method.

scholarly journals Variation of Burkholderia cenocepacia cell wall morphology and mechanical properties during cystic fibrosis lung infection, assessed by atomic force microscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Amir Hassan ◽  
Miguel V. Vitorino ◽  
Tiago Robalo ◽  
Mário S. Rodrigues ◽  
Isabel Sá-Correia
Keyword(s):  
Mechanical Properties ◽  
Cystic Fibrosis ◽  
Atomic Force Microscopy ◽  
Cell Wall ◽  
Adaptive Evolution ◽  
Burkholderia Cenocepacia ◽  
Force Microscopy ◽  
Atomic Force ◽  
Morphology And Mechanical Properties

Abstract The influence that Burkholderia cenocepacia adaptive evolution during long-term infection in cystic fibrosis (CF) patients has on cell wall morphology and mechanical properties is poorly understood despite their crucial role in cell physiology, persistent infection and pathogenesis. Cell wall morphology and physical properties of three B. cenocepacia isolates collected from a CF patient over a period of 3.5 years were compared using atomic force microscopy (AFM). These serial clonal variants include the first isolate retrieved from the patient and two late isolates obtained after three years of infection and before the patient’s death with cepacia syndrome. A consistent and progressive decrease of cell height and a cell shape evolution during infection, from the typical rods to morphology closer to cocci, were observed. The images of cells grown in biofilms showed an identical cell size reduction pattern. Additionally, the apparent elasticity modulus significantly decreases from the early isolate to the last clonal variant retrieved from the patient but the intermediary highly antibiotic resistant clonal isolate showed the highest elasticity values. Concerning the adhesion of bacteria surface to the AFM tip, the first isolate was found to adhere better than the late isolates whose lipopolysaccharide (LPS) structure loss the O-antigen (OAg) during CF infection. The OAg is known to influence Gram-negative bacteria adhesion and be an important factor in B. cenocepacia adaptation to chronic infection. Results reinforce the concept of the occurrence of phenotypic heterogeneity and adaptive evolution, also at the level of cell size, form, envelope topography and physical properties during long-term infection.

scholarly journals Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

2013 ◽  
Vol 4 ◽  
pp. 815-833 ◽  
Author(s):  
Sidney R Cohen ◽  
Estelle Kalfon-Cohen
Keyword(s):  
Atomic Force Microscopy ◽  
Time And Space ◽  
Material Response ◽  
Force Microscopy ◽  
Atomic Force ◽  
Important Phenomenon ◽  
Comparative Review ◽  
Key Techniques ◽  
Dynamic Nanoindentation

Viscoelasticity is a complex yet important phenomenon that drives material response at different scales of time and space. Burgeoning interest in nanoscale dynamic material mechanics has driven, and been driven by two key techniques: instrumented nanoindentation and atomic force microscopy. This review provides an overview of fundamental principles in nanoindentation, and compares and contrasts these two techniques as they are used for characterization of viscoelastic processes at the nanoscale.

Determining Mechanical Properties of Escherichia Coli by Nanoindentation

2012 ◽  
Vol 1424 ◽  
Author(s):  
C. A. Wright ◽  
C.J. Sullivan ◽  
B. Crawford ◽  
L.D. Britt ◽  
M.A. Mamun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Properties ◽  
Cell Wall ◽  
Contact Area ◽  
Solute Concentration ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
A Cell ◽  
Afm Cantilever

ABSTRACTEscherichia coli, like other gram-negative bacteria, is protected from the surrounding harsh environment by a cell wall consisting of the peptidoglycan and outer membrane. Whereas the cytoplasmic membrane is the selective barrier, the cell wall provides mechanical strength for the cell. As bacteria navigate various environments, osmotic pressure can change dramatically due to changes in local solute concentration. The peptidoglycan together with the cellular proteins mitigates the osmotic stress that would otherwise cause lysis. The mechanical properties of E. coli cells and its individual layers have been largely indeterminable until the recent development of probe-based measurement tools. Since their invention, scientists have reported significant data measuring elasticity, modulus, and stiffness using atomic force microscopy (AFM). Fundamentally, in order to determine these mechanical properties through probe-based techniques, the contact area and load should be well defined. The load can be precisely calculated through the AFM cantilever spring constant. However, the silicon tip contact area can only be estimated, potentially leading to compounding uncertainties. Therefore, we developed a methodology to determine nanomechanical properties of E. coli using a nanoindenter.

Microscopic Methods for Characterization of Selected Surface Properties of Biodegradable, Nanofibrous Tissue Engineering Scaffolds

2017 ◽  
Vol 890 ◽  
pp. 213-216 ◽  
Author(s):  
Adrian Chlanda ◽  
Ewa Kijeńska ◽  
Wojciech Święszkowski
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Force Spectroscopy ◽  
Operating Mode ◽  
Tissue Engineering Scaffolds ◽  
Force Microscopy ◽  
Atomic Force

Biodegradable polymeric fibers with nanoand submicron diameters, produced by electrospinning can be used as scaffolds in tissue engineering. It is necessary to characterize their mechanical properties especially at the nanoscale. The Force Spectroscopy is suitable atomic force microscopy mode, which allows to probe mechanical properties of the material, such as: reduced Young's modulus, deformation, adhesion, and dissipation. If combined with standard operating mode: contact or semicontact, it will also provide advanced topographical analysis. In this paper we are presenting results of Force Spectroscopy characterization of two kinds of electrospun fibers: polycaprolactone and polycaprolactone with hydroxyapatite addition. The average calculated from Johnson-Kendall-Roberts theory Young's modulus was 4 ± 1 MPa for pure polymer mesh and 20 ± 3 MPa for composite mesh.

scholarly journals Influence of hematite nanorods on the mechanical properties of epoxy resin

2017 ◽  
Vol 82 (4) ◽  
pp. 437-447 ◽  
Author(s):  
Gordana Bogdanovic ◽  
Tijana Kovac ◽  
Enis Dzunuzovic ◽  
Milena Spírková ◽  
Phillip Ahrenkiel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Microstructural Characterization ◽  
Uniform Size ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Uniform Size Distribution ◽  
Tensile Toughness

The mechanical properties of nanocomposites obtained by incorporation of fairly uniform hematite nanorods (?-Fe2O3 NRs) into epoxy resin were studied as a function of the content of the inorganic phase. A thorough microstructural characterization of the ?-Fe2O3 NRs and the nanocomposites was performed using transmission electron microscopy (TEM) and atomic force microscopy (AFM). The TEM measurements revealed rod-like morphology of the nanofiller with a uniform size distribution (8.5 nm?170 nm, diameter?length). High-magnification TEM and AFM measurements indicated agglomeration of ?-Fe2O3 NRs embedded in the epoxy resin. Stress at break, strain at break, elastic modulus and tensile toughness of the nanocomposites were compared with the data obtained for pure epoxy resin. Significant influence of nanofiller on the mechanical properties of epoxy resin, as well as on the glass transition temperature, could be noticed for samples with low contents of the inorganic phase (up to 1 wt. %).

Characterization of surface microroughness of silicon wafers by a multipass Fabry–Perot Rayleigh–Brillouin scattering spectrometer

1996 ◽  
Vol 11 (4) ◽  
pp. 878-883
Author(s):  
Lu Taijing ◽  
S. C. Ng ◽  
J. Furukawa ◽  
H. Furuya
Keyword(s):  
Atomic Force Microscopy ◽  
Brillouin Scattering ◽  
Scattered Light ◽  
Mapping Technique ◽  
Inhomogeneous Distribution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fabry Perot ◽  
Surface Microroughness

Surface microroughness of various Si(100) wafers was detected and characterized by a 180° backscattering Rayleigh–Brillouin scattering spectrometer (RBSS), and measured by an atomic force microscopy (AFM). The intensity of the scattered light from the wafers is found to increase with increasing surface microroughness which was measured by AFM. By scanning across the wafer, the inhomogeneous distribution of surface microroughness is detected and characterized. The system can be easily developed into a mapping technique. The results of the surface microroughness detected by AFM and RBSS suggest that they are complementary for the characterization of the surface microroughness from a microarea to a whole wafer.

scholarly journals The Influence of Nanometals, Dispersed in the Electrophoretic Nanohydroxyapatite Coatings on the Ti13Zr13Nb Alloy, on Their Morphology and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1638
Author(s):  
Michał Bartmański ◽  
Łukasz Pawłowski ◽  
Aleksandra Mielewczyk-Gryń ◽  
Gabriel Strugała ◽  
Krzysztof Rokosz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Optical Emission Spectroscopy ◽  
Physical And Mechanical Properties ◽  
Optical Emission ◽  
Properties Of Coatings ◽  
X Ray ◽  
Force Microscopy ◽  
Copper Addition ◽  
Atomic Force ◽  
Chemical And Phase Compositions

In this work, nanohydroxyapatite coatings with nanosilver and nanocopper have been fabricated and studied. The presented results concern coatings with a chemical composition that has never been proposed before. The present research aims to characterize the effects of nanosilver and nanocopper, dispersed in nanohydroxyapatite coatings and deposited on a new, non-toxic Ti13Zr13Nb alloy, on the physical and mechanical properties of coatings. The coatings were obtained by a one-stage electrophoretic process. The surface topography, and the chemical and phase compositions of coatings were examined with scanning electron microscopy, atomic force microscopy, X-ray diffractometry, glow discharge optical emission spectroscopy, and energy-dispersive X-ray spectroscopy. The mechanical properties of coatings were determined by nanoindentation tests, while coatings adhesion was determined by nanoscratch tests. The results demonstrate that copper addition increases the hardness and adhesion. The presence of nanosilver has no significant influence on the adhesion of coatings.

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