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Direct Measurement of the Surface Tension of a Soft Elastic Hydrogel: Exploration of Elasto-Capillary Instability in Adhesion
TLDR
A linear stability analysis confirmed that this long wavelength instability is due to an elastocapillary effect and suggests some new results related to the role of the finite dilation of a material in interfacial pattern formation that may have nontrivial consequences in the adhesive delamination of very thin and/or soft elastic films via self-generated cracks.Abstract:
An adhesively stressed thin film of a soft hydrogel confined between two rigid flat substrates auto-roughens with its dominant wavelength exhibiting pronounced dependence on the film thickness (H). A linear stability analysis confirmed that this long wavelength instability (~7H) is due to an elasto-capillary effect, the implementation of which required direct measurements of the surface tension and the elasticity of the gel. The surface tension of the gel was estimated from the fundamental spherical harmonic of a hemispherical cap of the gel that was excited by an external noise. The shear modulus of the gel was determined from its resonant shear mode in a confined geometry. During the course of this study, it was found that a high density steel ball submerges itself inside the gel by balancing its excess weight with the accumulated strain induced elastic force that allows another estimation of its elastic modulus. The large ratio (1.8 mm) of the surface tension to its elasticity ascertains the role of elasto-capillarity in the adhesion induced pattern formation with such gels. Experimental results are in accord with a linear stability analysis that predicts that the rescaled wavelength is linear with H, which modifies the conventional stress to pull-off a rigid flat object from a very soft film by a multiplicative factor. The analysis also suggests some new results related to the role of the finite dilation of a material in interfacial pattern formation that may have non-trivial consequences in the adhesive delamination of very thin and/or soft elastic films via self-generated cracks.read more
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Journal ArticleDOI
Elastocapillarity: Surface Tension and the Mechanics of Soft Solids
TL;DR: In this paper, the authors outline the theory of surface stresses from both mechanical and thermodynamic perspectives, emphasizing the relationship between surface stress and surface energy, and highlight how surface stresses cause dramatic departures from classic theories for wetting (Young-Dupre), adhesion (Johnson-Kendall-Roberts), and composites (Eshelby).
Journal ArticleDOI
Stiffening solids with liquid inclusions
Robert W. Style,Robert W. Style,Rostislav Boltyanskiy,Benjamin Allen,Katharine Jensen,Henry P. Foote,John S. Wettlaufer,John S. Wettlaufer,John S. Wettlaufer,Eric R. Dufresne +9 more
TL;DR: In this paper, the authors show that when the droplets are small enough, material can become stiffer, highlighting a role for surface tension in embedded with fluid inclusions, and demonstrate that the surface tension increases with the size of the inclusions.
Journal ArticleDOI
Assessment methodologies for extrusion-based bioink printability.
Gregory J. Gillispie,Peter M. Prim,Joshua S. Copus,Joshua S. Copus,John P. Fisher,Antonios G. Mikos,James J. Yoo,James J. Yoo,Anthony Atala,Anthony Atala,Sang Jin Lee,Sang Jin Lee +11 more
TL;DR: A review of measures used to assess the printability of extrusion-based bioinks in an attempt to assist researchers during the bioink development process and to standardize these printability measurements between researchers.
Journal ArticleDOI
Effects of surface tension on the adhesive contact of a rigid sphere to a compliant substrate
TL;DR: A numerical solution of the problem of indentation of an elastic half-space by a rigid sphere showing the transition between the classical Johnson-Kendall-Roberts (JKR) deformation and a liquid-like deformation in the absence of external load and gravity is presented.
Journal ArticleDOI
Liquid Droplets on a Highly Deformable Membrane.
TL;DR: This work examines the deformation produced by microdroplets atop thin elastomeric and glassy free-standing films and finds that if the membrane has an anisotropic tension, the droplets are no longer spherical but become elongated along the direction of high tension.
References
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Journal ArticleDOI
Disc electrophoresis – ii method and application to human serum proteins*
TL;DR: The technique of disc electrophoresis has been presented, including a discussion of the technical variables with special reference to the separation of protein fractions of normal human serum.
Book
A treatise on the mathematical theory of elasticity
TL;DR: Webb's work on elasticity as mentioned in this paper is the outcome of a suggestion made to me some years ago by Mr R. R. Webb that I should assist him in the preparation of a work on Elasticity.
Journal ArticleDOI
Surface energy and the contact of elastic solids
TL;DR: In this paper, the influence of surface energy on the contact between elastic solids is discussed and an analytical model for its effect upon the contact size and the force of adhesion between two lightly loaded spherical solid surfaces is presented.
Journal ArticleDOI
Hydrogels for biomedical applications.
TL;DR: The composition and synthesis of hydrogels, the character of their absorbed water, and permeation of solutes within their swollen matrices are reviewed to identify the most important properties relevant to their biomedical applications.
Journal ArticleDOI
The Penetration of a Fluid into a Porous Medium or Hele-Shaw Cell Containing a More Viscous Liquid
TL;DR: In this paper, it was shown that a flow is possible in which equally spaced fingers advance steadily at very slow speeds, such that behind the tips of the advancing fingers the widths of the two columns of fluid are equal.