AFM Based Nanomechanical Characterization of Cellulose Nanofibril

2020 ◽  
Vol 54 (28) ◽  
pp. 4487-4493 ◽  
Author(s):  
M Subbir Parvej ◽  
Xinnan Wang ◽  
Long Jiang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Natural Fibers ◽  
Longitudinal Direction ◽  
Cellulose Nanofibril ◽  
Force Microscopy ◽  
Atomic Force ◽  
Main Factors ◽  
Almost All

Cellulose nanofibril (CNF) is the fundamental unit of almost all types of natural fibers and is regarded as one of the main factors that influence their mechanical properties. Besides, owing to having a high aspect ratio, it is increasingly being used in the research of nanocomposite as a reinforcement recently. In order to utilize CNF as reinforcement more effectively, it is important to have a comprehensive idea about the mechanical properties of individual CNFs. Most of the studies are focused on the elastic modulus in the longitudinal direction, but the study of the elastic modulus in the transverse direction is still lacking. In this study, a single strand of CNF was subjected to an atomic force microscopy to characterize the surface morphology of CNF and determine the transverse elastic modulus through nanoindentation. The transverse elastic modulus of CNF was calculated to be 6.9 [Formula: see text] 0.4 GPa using extended JKR model.

scholarly journals A Universal Model for the Log-Normal Distribution of Elasticity in Polymeric Gels and Its Relevance to Mechanical Signature of Biological Tissues

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet
Keyword(s):  
Elastic Modulus ◽  
Normal Distribution ◽  
Biological Tissues ◽  
Force Microscopy ◽  
Polymeric Gels ◽  
Atomic Force ◽  
Clear Explanation ◽  
Log Normal ◽  
Log Normal Distribution

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.

scholarly journals Mechanical Characterization of a Dynamic and Tunable Methacrylated Hyaluronic Acid Hydrogel

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Matthew G. Ondeck ◽  
Adam J. Engler
Keyword(s):  
Hyaluronic Acid ◽  
Elastic Modulus ◽  
Monomer Concentration ◽  
Degree Of Polymerization ◽  
Force Microscopy ◽  
3T3 Fibroblasts ◽  
Atomic Force ◽  
Spread Area ◽  
Nih 3T3

Hyaluronic acid (HA) is a commonly used natural polymer for cell scaffolding. Modification by methacrylate allows it to be polymerized by free radicals via addition of an initiator, e.g., light-sensitive Irgacure, to form a methacrylated hyaluronic acid (MeHA) hydrogel. Light-activated crosslinking can be used to control the degree of polymerization, and sequential polymerization steps allow cells plated onto or in the hydrogel to initially feel a soft and then a stiff matrix. Here, the elastic modulus of MeHA hydrogels was systematically analyzed by atomic force microscopy (AFM) for a number of variables including duration of UV exposure, monomer concentration, and methacrylate functionalization. To determine how cells would respond to a specific two-step polymerization, NIH 3T3 fibroblasts were cultured on the stiffening MeHA hydrogels and found to reorganize their cytoskeleton and spread area upon hydrogel stiffening, consistent with cells originally cultured on substrates of the final elastic modulus.

Nanoscale Mechanical Properties of Polymer Composites: Changes in Elastic Modulus and Measurement of Ion Penetration Depth Due to α-radiation

2000 ◽  
Vol 15 (4) ◽  
pp. 838-841
Author(s):  
Allen T. Chien ◽  
Tom Felter ◽  
James D. LeMay ◽  
Mehdi Balooch
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Penetration Depth ◽  
Depth Profiling ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force ◽  
Sample Edge ◽  
Composite Samples ◽  
Ion Penetration

The local mechanical properties of silica-reinforced silicone composites were investigated using a modified atomic force microscopy technique. Elastic modulus measurements (1.5 ± 0.1 MPa) are consistent with bulk measurements (1.9 MPa), and changes in the modulus at the surface of the composite samples (E = 1.5 to 3.5 MPa) were observed as a result of α-irradiation (dose = 1.7 × 1010 to 2.0 × 1012 α/cm2). The sensitivity of the technique was demonstrated by a detectable change in modulus at even the small dose of 1.7 × 1010 α/cm2. The penetration depth of the α-particles into the material, estimated to be 22 ± 2 μm from the sample edge, was determined by cross-section depth profiling; and modeling of the ion penetration depth using transport of ions in matter codes (24.4 ± 0.4 μm) closely matched experimental observations.

Atomic force microscopy-based nanomechanical characterization of kenaf fiber

2019 ◽  
Vol 54 (15) ◽  
pp. 2065-2071 ◽  
Author(s):  
M Subbir Parvej ◽  
Xinnan Wang ◽  
Joseph Fehrenbach ◽  
Chad A Ulven
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Elastic Modulus ◽  
Adhesion Force ◽  
Fiber Surface ◽  
Gauge Length ◽  
Hibiscus Cannabinus ◽  
Kenaf Fiber ◽  
Force Microscopy ◽  
Atomic Force

Kenaf ( Hibiscus cannabinus L.) fiber is being extensively used as a reinforcement material in composites due to its excellent mechanical properties. To use this fiber more efficiently, it is necessary to understand its mechanical properties at micro/nano meter scale. Despite the evidence of some past studies to determine the elastic modulus of kenaf fiber, most of them were performed on fiber bundles. Bundle-based method to find the elastic moduli has some obvious issues of foreign materials being present, incorrect gauge length, and sample diameter due to void spaces. These issues pose as obvious hurdles to determine the elastic modulus accurately. In this study, individual kenaf micro fiber was used to find elastic modulus in the radial direction. The radial elastic modulus of the fiber was characterized by atomic force microscopy-based nanoindentation. To determine the radial elastic modulus from the force versus sample deformation data, the extended Johnson–Kendall–Roberts model was used which considered adhesion force from the fiber surface. The radial elastic modulus of the kenaf fiber was found to be 2.3 GPa.

scholarly journals Elucidating nanoscale mechanical properties of diabetic human adipose tissue using atomic force microscopy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
J. K. Wenderott ◽  
Carmen G. Flesher ◽  
Nicki A. Baker ◽  
Christopher K. Neeley ◽  
Oliver A. Varban ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metabolic Disease ◽  
Atomic Force Microscopy ◽  
Adipose Tissue ◽  
Elastic Modulus ◽  
Tissue Mechanics ◽  
Health Concern ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Impact

AbstractObesity-related type 2 diabetes (DM) is a major public health concern. Adipose tissue metabolic dysfunction, including fibrosis, plays a central role in DM pathogenesis. Obesity is associated with changes in adipose tissue extracellular matrix (ECM), but the impact of these changes on adipose tissue mechanics and their role in metabolic disease is poorly defined. This study utilized atomic force microscopy (AFM) to quantify difference in elasticity between human DM and non-diabetic (NDM) visceral adipose tissue. The mean elastic modulus of DM adipose tissue was twice that of NDM adipose tissue (11.50 kPa vs. 4.48 kPa) to a 95% confidence level, with significant variability in elasticity of DM compared to NDM adipose tissue. Histologic and chemical measures of fibrosis revealed increased hydroxyproline content in DM adipose tissue, but no difference in Sirius Red staining between DM and NDM tissues. These findings support the hypothesis that fibrosis, evidenced by increased elastic modulus, is enhanced in DM adipose tissue, and suggest that measures of tissue mechanics may better resolve disease-specific differences in adipose tissue fibrosis compared with histologic measures. These data demonstrate the power of AFM nanoindentation to probe tissue mechanics, and delineate the impact of metabolic disease on the mechanical properties of adipose tissue.

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.

Apparent elastic modulus and hysteresis of skeletal muscle cells throughout differentiation

2002 ◽  
Vol 283 (4) ◽  
pp. C1219-C1227 ◽  
Author(s):  
Amy M. Collinsworth ◽  
Sarah Zhang ◽  
William E. Kraus ◽  
George A. Truskey
Keyword(s):  
Mechanical Properties ◽  
Skeletal Muscle ◽  
Elastic Modulus ◽  
Viscoelastic Behavior ◽  
Muscle Cells ◽  
Cytochalasin D ◽  
Skeletal Muscle Cells ◽  
Force Microscopy ◽  
Relative Contribution ◽  
Atomic Force

The effect of differentiation on the transverse mechanical properties of mammalian myocytes was determined by using atomic force microscopy. The apparent elastic modulus increased from 11.5 ± 1.3 kPa for undifferentiated myoblasts to 45.3 ± 4.0 kPa after 8 days of differentiation ( P< 0.05). The relative contribution of viscosity, as determined from the normalized hysteresis area, ranged from 0.13 ± 0.02 to 0.21 ± 0.03 and did not change throughout differentiation. Myosin expression correlated with the apparent elastic modulus, but neither myosin nor β-tubulin were associated with hysteresis. Microtubules did not affect mechanical properties because treatment with colchicine did not alter the apparent elastic modulus or hysteresis. Treatment with cytochalasin D or 2,3-butanedione 2-monoxime led to a significant reduction in the apparent elastic modulus but no change in hysteresis. In summary, skeletal muscle cells exhibited viscoelastic behavior that changed during differentiation, yielding an increase in the transverse elastic modulus. Major contributors to changes in the transverse elastic modulus during differentiation were actin and myosin.

Mapping of Nanoscale Mechanical Properties of Polymers in Quasi-static and Oscillatory Atomic Force Microscopy Modes

MRS Advances ◽  
2016 ◽  
Vol 1 (40) ◽  
pp. 2763-2768 ◽  
Author(s):  
Sergei Magonov ◽  
Marko Surtchev ◽  
John Alexander ◽  
Ivan Malovichko ◽  
Sergey Belikov
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Elastic Modulus ◽  
Polymer Materials ◽  
Work Of Adhesion ◽  
Force Microscopy ◽  
Atomic Force ◽  
Time Dependencies ◽  
Force Curves ◽  
20 Nm

ABSTRACTRecent advances in studies of local mechanical properties of polymers with different atomic force microscopy techniques (contact, Hybrid and amplitude modulation modes) are described in interplay between experiment and theory. Analysis of force curves and time dependencies of probe response to sample compliance, which were recorded on a number of polymer materials at various temperatures, leads to quantitative mapping of specific mechanical properties (elastic modulus, work of adhesion, etc). High spatial resolution of elastic modulus mapping (10-20 nm) is illustrated in measurements of lamellar structures of several polymers. Challenges of examination of viscoelastic properties are pointed out and a possible solution is presented.

scholarly journals Quantitative Nanomechanical Mapping of Polyolefin Elastomer at Nanoscale with Atomic Force Microscopy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shuting Zhang ◽  
Yihui Weng ◽  
Chunhua Ma
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mechanical Response ◽  
Adhesion Force ◽  
Time Dependent ◽  
Surface Adhesion ◽  
Force Microscopy ◽  
Mechanics Model ◽  
Atomic Force ◽  
Force Volume

AbstractElastomeric nanostructures are normally expected to fulfill an explicit mechanical role and therefore their mechanical properties are pivotal to affect material performance. Their versatile applications demand a thorough understanding of the mechanical properties. In particular, the time dependent mechanical response of low-density polyolefin (LDPE) has not been fully elucidated. Here, utilizing state-of-the-art PeakForce quantitative nanomechanical mapping jointly with force volume and fast force volume, the elastic moduli of LDPE samples were assessed in a time-dependent fashion. Specifically, the acquisition frequency was discretely changed four orders of magnitude from 0.1 up to 2 k Hz. Force data were fitted with a linearized DMT contact mechanics model considering surface adhesion force. Increased Young’s modulus was discovered with increasing acquisition frequency. It was measured 11.7 ± 5.2 MPa at 0.1 Hz and increased to 89.6 ± 17.3 MPa at 2 kHz. Moreover, creep compliance experiment showed that instantaneous elastic modulus E1, delayed elastic modulus E2, viscosity η, retardation time τ were 22.3 ± 3.5 MPa, 43.3 ± 4.8 MPa, 38.7 ± 5.6 MPa s and 0.89 ± 0.22 s, respectively. The multiparametric, multifunctional local probing of mechanical measurement along with exceptional high spatial resolution imaging open new opportunities for quantitative nanomechanical mapping of soft polymers, and can potentially be extended to biological systems.

Sign in / Sign up

Export Citation Format

Share Document