scholarly journals Contact probing of prestressed adhesive membranes of living cells

2021 ◽  
Vol 379 (2203) ◽  
pp. 20200289 ◽  
Author(s):  
Feodor M. Borodich ◽  
Boris A. Galanov ◽  
Leon M. Keer ◽  
Maria M. Suarez-Alvarez
Keyword(s):  
Mechanical Properties ◽  
Cell Membranes ◽  
Contact Problems ◽  
Adhesive Contact ◽  
Living Cells ◽  
Work Of Adhesion ◽  
Biological Cells ◽  
Crucial Importance ◽  
Adhesive Properties ◽  
Jkr Theory

Atomic force microscopy (AFM) studies of living biological cells is one of main experimental tools that enable quantitative measurements of deformation of the cells and extraction of information about their structural and mechanical properties. However, proper modelling of AFM probing and related adhesive contact problems are of crucial importance for interpretation of experimental data. The Johnson–Kendall–Roberts (JKR) theory of adhesive contact has often been used as a basis for modelling of various phenomena including cell-cell interactions. However, strictly speaking the original JKR theory is valid only for contact of isotropic linearly elastic spheres, while the cell membranes are often prestressed. For the first time, effects caused by molecular adhesion for living cells are analytically studied taking into account the mechanical properties of cell membranes whose stiffness depends on the level of the tensile prestress. Another important question is how one can extract the work of adhesion between the probe and the cell. An extended version of the Borodich-Galanov method for non-direct extraction of elastic and adhesive properties of contacted materials is proposed to apply to experiments of cell probing. Evidently, the proposed models of adhesive contact for cells with prestressed membranes do not cover all types of biological cells because the structure and properties of the cells may vary considerably. However, the obtained results can be applied to many types of smooth cells and can be used to describe initial stages of contact and various other processes when effects of adhesion are of crucial importance. This article is part of a discussion meeting issue ‘A cracking approach to inventing new tough materials: fracture stranger than friction’.

Non-direct estimations of adhesive and elastic properties of materials by depth-sensing indentation

2008 ◽  
Vol 464 (2098) ◽  
pp. 2759-2776 ◽  
Author(s):  
Feodor M Borodich ◽  
Boris A Galanov
Keyword(s):  
Experimental Data ◽  
Elastic Properties ◽  
Measurement Errors ◽  
Direct Determination ◽  
Adhesive Contact ◽  
Work Of Adhesion ◽  
Displacement Curve ◽  
Depth Sensing ◽  
Adhesive Properties ◽  
Force Displacement

Using the connection between depth-sensing indentation by spherical indenters and mechanics of adhesive contact, a new method for non-direct determination of adhesive and elastic properties of contacting materials is proposed. At low loads, the force–displacement curves reflect not only elastic properties but also adhesive properties of the contact, and therefore one can try to extract from experiments both the elastic characteristics of contacting materials (such as the reduced elastic modulus) and characteristics of molecular adhesion (such as the work of adhesion and the pull-off force) using a non-direct approach. The direct methods of estimations of the adhesive characteristics of materials currently used in experiments are rather complicated due to the instability of the experimental force–displacement diagrams for ultra-low tensile forces. The proposed method is based on the use of the stable experimental data for the elastic stage of the force–displacement curve and the mechanics of adhesive contact for spherical indenters. Since the experimental data always have some measurement errors, mathematical techniques for solving ill-posed problems are employed.

scholarly journals Adhesive contact problems for a thin elastic layer: Asymptotic analysis and the JKR theory

2018 ◽  
Vol 24 (5) ◽  
pp. 1405-1424 ◽  
Author(s):  
Feodor M. Borodich ◽  
Boris A. Galanov ◽  
Nikolay V. Perepelkin ◽  
Danila A. Prikazchikov
Keyword(s):  
Elastic Foundation ◽  
Elastic Layer ◽  
Order Approximation ◽  
Contact Problems ◽  
Adhesive Contact ◽  
Contact Radius ◽  
Direct Derivation ◽  
Compressible Elastic Layer ◽  
Jkr Theory ◽  
Thin Elastic Layer

Contact problems for a thin compressible elastic layer attached to a rigid support are studied. Assuming that the thickness of the layer is much less than the characteristic dimension of the contact area, a direct derivation of asymptotic relations for displacements and stress is presented. The proposed approach is compared with other published approaches. The cases are established when the leading-order approximation to the non-adhesive contact problems is equivalent to contact problem for a Winkler–Fuss elastic foundation. For this elastic foundation, the axisymmetric adhesive contact is studied in the framework of the Johnson–Kendall–Roberts (JKR) theory. The JKR approach has been generalized to the case of the punch shape being described by an arbitrary blunt axisymmetric indenter. Connections of the results obtained to problems of nanoindentation in the case that the indenter shape near the tip has some deviation from its nominal shape are discussed. For indenters whose shape is described by power-law functions, the explicit expressions are derived for the values of the pull-off force and for the corresponding critical contact radius.

How the work of adhesion affects the mechanical properties of silica-filled polymer composites

1994 ◽  
Vol 29 (9) ◽  
pp. 2406-2416 ◽  
Author(s):  
S. W. Shang ◽  
J. W. Williams ◽  
K. -J. M. Söderholm
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Work Of Adhesion ◽  
Filled Polymer

scholarly journals Anisotropic Mechanical Properties of Living Cells Revealed by Integrated Spinning Disk Confocal and Atomic Force Microscopy

2018 ◽  
Vol 114 (3) ◽  
pp. 513a
Author(s):  
Yuri M. Efremov ◽  
Mirian Velay-Lizancos ◽  
Daniel M. Suter ◽  
Pablo D. Zavattieri ◽  
Arvind Raman
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Living Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spinning Disk ◽  
Anisotropic Mechanical Properties

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

Determination of Cellular Mechanical Properties by Cell Poking, With an Application to Leukocytes

1990 ◽  
Vol 112 (3) ◽  
pp. 283-294 ◽  
Author(s):  
G. I. Zahalak ◽  
W. B. McConnaughey ◽  
E. L. Elson
Keyword(s):  
Mechanical Properties ◽  
Final Section ◽  
Mechanical Response ◽  
Living Cells ◽  
Micropipette Aspiration ◽  
Current Status ◽  
Technical Description ◽  
Analytical Results ◽  
Simple Models

In this paper we review the cell-poking technique as an approach for investigating the mechanical properties of living cells. We first summarize the rationale for the technique and the mainly qualitative results obtained so far. Then we provide a technical description of the instrument as it is configured at present. This is followed by a discussion of the current status of analytical results available for interpreting cell-poking measurements. In the final section we apply these results to an analysis of unmodulated and modulated lymphocytes and neutrophils, and conclude that the mechanical response of these leukocytes to indentation is not consistent with simple models developed by previous investigators on the basis of micropipette-aspiration experiments.

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