scholarly journals Spinning elastic beads: a route for simultaneous measurements of the shear modulus and the interfacial energy of soft materials

Soft Matter ◽  
2020 ◽  
Vol 16 (36) ◽  
pp. 8412-8421 ◽  
Author(s):  
Alessandro Carbonaro ◽  
Kennedy-Nexon Chagua-Encarnacion ◽  
Carole-Ann Charles ◽  
Ty Phou ◽  
Christian Ligoure ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Surface Energy ◽  
Shear Modulus ◽  
Interfacial Energy ◽  
Soft Materials ◽  
Elastic Materials ◽  
Energy Constant ◽  
Simultaneous Measurements

We demonstrate that the elastic modulus and the surface energy constant of soft elastic materials can be simultaneously measured by analysing the deformation of millimetric beads under centrifugal forcing.

Estimation of Interfacial Energies Based on the Shapes of Coherent Intragranular Precipitates

1999 ◽  
Vol 5 (S2) ◽  
pp. 864-865
Author(s):  
Xiao Chen ◽  
L. Rabenberg
Keyword(s):  
Solid Solution ◽  
Surface Energy ◽  
Interfacial Energy ◽  
Elastic Anisotropy ◽  
Ternary Alloys ◽  
Interfacial Energies ◽  
Simultaneous Measurements ◽  
Precise Shape ◽  
Invar Composition ◽  
Favorable Conditions

In a study of the precipitation and aging of Invar particles in Cu, we observed that the particles evolved from spherical to cuboidal as they grew in size. This behavior has been observed in other systems, and predicted by Voorhees et al. ; they showed that the precise shape of the particle is a balance between elastic anisotropy and surface energy. The correlation between our results and their predictions are very good. It is the purpose of this note to point out that simultaneous measurements of size, shape, and mismatch of a coherent particle can be used to estimate the interfacial energy under favorable conditions.Ternary alloys consisting of Cu - 12.8 wt% Ni -7.2 wt% Fe were arc-melted, held at 1030°C to develop extended regions of the Cu-rich solid solution, quenched, then aged at various times and temperatures to develop FCC precipitates near the Invar composition in the FCC Cu matrix.

Evidence of Supersolidity in Rotating Solid Helium

Science ◽  
2010 ◽  
Vol 330 (6010) ◽  
pp. 1512-1515 ◽  
Author(s):  
H. Choi ◽  
D. Takahashi ◽  
K. Kono ◽  
E. Kim
Keyword(s):  
Elastic Modulus ◽  
Shear Modulus ◽  
Solid Helium ◽  
Torsional Oscillator ◽  
Helium 4 ◽  
Simultaneous Measurements ◽  
Superfluid Component ◽  
Zero Viscosity ◽  
Resonant Period ◽  
Substantial Change

Supersolidity, the appearance of zero-viscosity flow in solids, was first indicated in helium-4 torsional oscillator (TO) experiments. In this apparatus, the irrotationality of the superfluid component causes it to decouple from the underlying normal solid, leading to a reduction in the resonant period of the TO. However, the resonant period may be altered for reasons other than supersolidity, such as the temperature dependence of the elastic modulus of solid helium. Superimposing rotation onto oscillatory measurements may distinguish between supersolidity and classical effects. We performed such simultaneous measurements of the TO and the shear modulus, and observed substantial change in the resonant period with rotational speed where the modulus remained unchanged. This contrasting behavior suggests that the decrease in the TO period is a result of supersolidity.

scholarly journals Shear modulus and yield stress of foams: contribution of interfacial elasticity

Soft Matter ◽  
2021 ◽  
Vol 17 (14) ◽  
pp. 3937-3944
Author(s):  
Annika R. Völp ◽  
Norbert Willenbacher
Keyword(s):  
Elastic Modulus ◽  
Block Copolymer ◽  
Shear Modulus ◽  
Yield Stress ◽  
Protein Food ◽  
General Correlation

A general correlation of foam shear modulus G0 and yield stress τy with the interfacial elastic modulus of foaming solutions in shear and dilation E∞ was found for surfactant, block-copolymer, protein, food, and particle-stabilized foams.

scholarly journals Effect of surface bending and stress on the transmission of line force to an elastic substrate

2018 ◽  
Vol 474 (2215) ◽  
pp. 20170775 ◽  
Author(s):  
Chung Yuen Hui ◽  
Zezhou Liu ◽  
Anand Jagota
Keyword(s):  
Elastic Modulus ◽  
Surface Stress ◽  
Broad Class ◽  
Local Stress ◽  
Soft Materials ◽  
Elastic Substrate ◽  
Capillary Length ◽  
Singular Stress ◽  
Line Load ◽  
Line Force

For a broad class of soft materials their surface stress can strongly influence mechanical behaviour. For example, a line force applied to the surface of an elastic substrate is locally supported by surface stress over an elasto-capillary length l c (surface stress/elastic modulus). Surface stress regularizes the otherwise highly singular stress and strain fields. However, surface such as lipid bilayer interfaces can also resist deformation by bending. This has not been studied either by experiments or theories. We analyse a theoretical model of the response of a half-space to a line force when the surface carries both a stress and resistance to bending. We find that surface bending further regularizes the singular fields. The local stress field near the line load can be separated into three regions. Region 1 occupies distances from the line load smaller than an elasto-capillary bending length l b (bending stiffness/elastic modulus to the 1/3 power) where surface bending dominates and the elastic stress and strains are continuous. Region 2 occupies intermediate distances between l b and l c   ( > l b ) where surface stress dominates. At distances larger than l c we retrieve the classical elasticity solution. The size of region 2 depends on κ = l c / l b and vanishes for small l c .

Quantitative mechanical analysis of indentations on layered, soft elastic materials

Soft Matter ◽  
2019 ◽  
Vol 15 (8) ◽  
pp. 1776-1784 ◽  
Author(s):  
Bryant L. Doss ◽  
Kiarash Rahmani Eliato ◽  
Keng-hui Lin ◽  
Robert Ros
Keyword(s):  
Atomic Force Microscopy ◽  
Elastic Modulus ◽  
Cell Mechanics ◽  
Biological Samples ◽  
Mechanical Analysis ◽  
Elastic Materials ◽  
Mechanical Heterogeneity ◽  
Popular Method ◽  
Force Microscopy ◽  
Atomic Force

Atomic force microscopy (AFM) is becoming an increasingly popular method for studying cell mechanics, however the existing analysis tools for determining the elastic modulus from indentation experiments are unable to quantitatively account for mechanical heterogeneity commonly found in biological samples.

scholarly journals Adhesive interactions of geckos with wet and dry fluoropolymer substrates

2015 ◽  
Vol 12 (108) ◽  
pp. 20150464 ◽  
Author(s):  
Alyssa Y. Stark ◽  
Daniel M. Dryden ◽  
Jeffrey Olderman ◽  
Kelly A. Peterson ◽  
Peter H. Niewiarowski ◽  
...  
Keyword(s):  
Surface Energy ◽  
Interfacial Energy ◽  
Substrate Surface ◽  
Energy Calculations ◽  
Bioinspired Design ◽  
Interfacial Energies ◽  
Normal Adhesion ◽  
Adhesive Interactions ◽  
Low Shear

Fluorinated substrates like Teflon ® (poly(tetrafluoroethylene); PTFE) are well known for their role in creating non-stick surfaces. We showed previously that even geckos, which can stick to most surfaces under a wide variety of conditions, slip on PTFE. Surprisingly, however, geckos can stick reasonably well to PTFE if it is wet. In an effort to explain this effect, we have turned our attention to the role of substrate surface energy and roughness when shear adhesion occurs in media other than air. In this study, we removed the roughness component inherent to commercially available PTFE and tested geckos on relatively smooth wet and dry fluoropolymer substrates. We found that roughness had very little effect on shear adhesion in air or in water and that the level of fluorination was most important for shear adhesion, particularly in air. Surface energy calculations of the two fluorinated substrates and one control substrate using the Tabor–Winterton approximation and the Young–Dupré equation were used to determine the interfacial energy of the substrates. Using these interfacial energies we estimated the ratio of wet and dry normal adhesion for geckos clinging to the three substrates. Consistent with the results for rough PTFE, our predictions show a qualitative trend in shear adhesion based on fluorination, and the quantitative experimental differences highlight the unusually low shear adhesion of geckos on dry smooth fluorinated substrates, which is not captured by surface energy calculations. Our work has implications for bioinspired design of synthetics that can preferentially stick in water but not in air.

Characterization of Chemically and Topographically Modified Siloxane Elastomer for Controlled Cell Growth

2001 ◽  
Vol 711 ◽  
Author(s):  
Amy L. Gibson ◽  
Leslie H. Wilson ◽  
Wade R. Wilkerson ◽  
Adam W. Feinberg ◽  
Charles A. Seegert ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Cell Growth ◽  
Surface Energy ◽  
Cellular Response ◽  
Silicone Oil ◽  
Control Cell ◽  
Weight Percent ◽  
Mechanical Analysis ◽  
Specific Cell ◽  
Silicone Oils

ABSTRACTA main limitation of biomedical devices is the inability to start, stop, and control cell growth making it crucial to develop biomaterial surfaces that induce a desired cellular response. Micropatterns of ridges and pillars were created in a siloxane elastomer (Dow Corning) by casting against epoxy replicates of a micromachined silicon wafer. Silicone oils were incorporated to determine the change in modulus and surface energy caused by these additives. SEM and white light interference profilometry verified that the micropatterning process produced high fidelity, low defect micropatterns. Mechanical analysis indicated that varying the viscosity, weight percent and functionality of the added silicone oil could change the elastic modulus by over an order of magnitude (0.1-2.3 MPa). As a self-wetting resin, silicone oils migrate to the surface, hence changing the surface properties from the bulk. Both topographical and chemical features define the surface energy, which in combination with elastic modulus, dictate biological activity. The results imply that the morphology, mechanical properties and surface energy of the siloxane elastomer can be modified to elicit a specific cell response as a function of engineered topographical and chemical functionalization.

First-Principles Study of the Elastic Properties of Hexagonal Phase ScAx (A=H, He)

2013 ◽  
Vol 690-693 ◽  
pp. 1723-1727
Author(s):  
Kai Min Fan ◽  
Li Yang ◽  
Jing Tang ◽  
Qing Qiang Sun ◽  
Xiao Tao Zu
Keyword(s):  
Elastic Modulus ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
First Principles ◽  
Poisson’S Ratio ◽  
Hexagonal Phase ◽  
Poisson's Ratio ◽  
First Principles Calculations ◽  
Charge Densities ◽  
Change Mechanism

First-principles calculations are performed to investigate the Young’s modulus, bulk modulus, shear modulus and Poisson’s ratio of hexagonal phase ScAx(A=H, He), where x=0, 0.0313, 0.125 and 0.25, represent the ratio of interstitial atoms A (A=H, He) to Sc atoms. The influences of hydrogen concentrations and helium concentrations on elastic modulus and Poisson’s ratio of ScAx(A=H, He) have been studied. The results indicate that hydrogen and helium have different effects on the elastic modulus of hexagonal phase scandium. The change mechanism of the Poisson’s ratio with the variation of the x ranging from 0 to 0.25 has also been studied in hexagonal phase ScAx(A=H, He). In addition, the changes in the charge densities of ScAxdue to the presence of hydrogen and helium have been calculated.

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