Analysis of nanoindentation of soft materials with an atomic force microscope

Notbohm, Jacob; Poon, B.; Ravichandran, G.

doi:10.1557/jmr.2011.252

Cited by 46 publications

(32 citation statements)

References 25 publications

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“…In real experiments, it is technically tricky to determine the point of zero penetration 14,[24][25][26][27] and find the corresponding force P 0 . Therefore, we use the pull-in force, P pi , i.e., the maximum negative force during the loading to approximate the force at zero penetration since the pull-in phenomenon is expected to occur near the contact point.…”

Section: Jkr Theorymentioning

confidence: 99%

Work of adhesion/separation between soft elastomers of different mixing ratios

Sanchez

2015

J. Mater. Res.

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Adhesion between soft matter is a universal mechanical problem in bio-engineering and bio-integration. The Johnson-Kendall-Roberts (JKR) method is widely used to measure the work of adhesion and work of separation between soft materials. In this study, the JKR theory is recaptured and three complementary dimensionless parameters are summarized to help design adhesion measurement experiments compatible with the JKR theory. The work of adhesion/separation between two commonly used soft elastomers, polydimethylsiloxane (PDMS, Sylgard Ò 184) and Ecoflex Ò 0300, is measured by the JKR method using a dynamical mechanical analyzer. Effects of base polymer to curing agent mixing ratio and solvent extraction are examined. A unified adhesion mechanism is proposed to explain the different adhesion behaviors. It is concluded that chain-matrix interaction is the most effective adhesion mechanism compared with chain-chain or matrix-matrix interactions. Chain-chain interaction obstructs chain-matrix interaction as it either blocks or entangles with surface chains which could have interacted with the matrix.

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Section: Jkr Theorymentioning

confidence: 99%

Work of adhesion/separation between soft elastomers of different mixing ratios

Sanchez

2015

J. Mater. Res.

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“…As a result, the mechanical properties determined using the AFM-based technique require an appropriate mathematical [36] or finite element analysis [37] model with embedded assumptions. To date, the mathematical model developed to interpret AFM force-displacement data for soft biological materials [38] has yet to be optimized for characterizing heterogeneous and multi-layered samples, such as cell walls. To address the intricate architectural nature of the cell wall, an appropriate model needs to be developed.…”

Section: Introductionmentioning

confidence: 99%

The mechanical properties of plant cell walls soft material at the subcellular scale: the implications of water and of the intercellular boundaries

Zamil

Puri

2015

J Mater Sci

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Subcellular mechanical characterization of the cell wall can provide important insights into the cell wall's functional organization, especially if the characterization is not confounded by extracellular factors and intercellular boundaries. However, due to the technical challenges associated with the microscale mechanical characterization of soft biological materials, subcellular investigations of the plant cell wall under tensile loading have yet to be properly performed. This study reports the mechanical characterization of primary onion epidermal cell wall profiles using a novel cryosection-based sample preparation method and a microelectromechanical system-based tensile testing protocol. At the subcellular scale, the cell wall showed biphasic behavior similar to tissue samples. However, instead of a transition zone between the linear elastic or viscoelastic and linear plastic zones, the subcellular-scale samples showed a plateau-like trend with a sharp drop in the modulus value. The critical ranges of stress (20-40 MPa) and strain (5-12 %) of the plateau zone were identified. A strain energy of 1.3 MJ m -3 was calculated at the midpoint of the critical stress-strain range; this value was in accordance with the previously estimated hydrogen bond energy of the cell wall. Subcellular-scale samples showed very large lateral/axial deformations (0.8 ± 0.13) at fracturing. In addition, investigating the cell wall's mechanical properties at three different water states showed that water is critical for the flow-like behavior of cell wall matrix polymers. These results at subcellular scale provide new insights into biological materials that possess a structural hierarchy at different length scales; which cannot be obtained from tissue-scale experiments.

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“…Recently the adhesive properties of polymer materials were studied using an AFM . The used approach was quite similar to some of approaches described in ref .…”

Section: Mechanics Of Adhesive Contact and Depth‐sensing Indentationmentioning

confidence: 99%

“…The used approach was quite similar to some of approaches described in ref . However, the authors of ref . did not use but rather they tried to find the best fit to the shifted JKR curve.…”

Section: Mechanics Of Adhesive Contact and Depth‐sensing Indentationmentioning

confidence: 99%

Evaluation of Adhesive and Elastic Properties of Polymers by the BG Method

Borodich

Galanov

Gorb³

et al. 2013

Macro Reaction Engineering

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The work of adhesion and the elastic contact modulus of the pair of interacting materials are a prerequesite in order to study adhesive interactions between solids. For small material samples, the contact modulus is usually evaluated by depth‐sensing indentation of sharp indenters, while the work of adhesion is determined by direct measurements of pull‐off force of a sphere. These measurements are unstable due to the instability of the load–displacement diagrams under tension, and they can be greatly affected by the roughness of the contacting solids. Using experiments for polyvinylsiloxane samples, it is shown how the work of adhesion and the elastic contact modulus of materials may be quantified using the BG method. This is a non‐direct method based on an inverse analysis of a stable region of the experimental force–displacement curves. The BG method is simple and robust. Nevertheless, the extracted values of both characteristics vary within the same polymer sample due to contact areas that possess interacting polymer molecules in various orientations. It was found that the average values of characteristics are very stable and the work of adhesion of polymers may be treated as a material parameter in statistical sense.

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Analysis of nanoindentation of soft materials with an atomic force microscope

Cited by 46 publications

References 25 publications

Work of adhesion/separation between soft elastomers of different mixing ratios

Work of adhesion/separation between soft elastomers of different mixing ratios

The mechanical properties of plant cell walls soft material at the subcellular scale: the implications of water and of the intercellular boundaries

Evaluation of Adhesive and Elastic Properties of Polymers by the BG Method

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