Poisson's Ratio of Monodomain Liquid Crystalline Elastomers

Ren, Wanting; McMullan, Philip J.; Griffin, Anselm C.

doi:10.1002/macp.200800265

Cited by 49 publications

(48 citation statements)

References 20 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Polydomain smectic MCLCEs have been extensively studied [20,[60][61][62][63][64][65][66][67]. Sánchez-Ferrer et al [64] reported the polydomain to monodomain (P-M) transition caused by uniaxial strain in these materials.…”

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

“…Three specimens of LCE1 were prepared: one in polydomain and the other two in mechanically induced monodomain states. An initial strain of 200% (λ = 3) was applied and approximately 130% of the strain was retained in the monodomain samples for prolonged periods of time [65]. Figure 7 shows the response characteristics of LCE1 when stretched along the directions parallel and perpendicular to n n , and also in the initially polydomain state.…”

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

“…Also, the width of the plateau region is considerably reduced when stretched parallel to . For stretching in the direction perpendicular to the stress-strain plateau extends up to a large strain (of ~500%) until the film breaks [65]. A volume preserving narrowing of the width is observed as the film is elongated [50].…”

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

See 2 more Smart Citations

Soft Elasticity in Main Chain Liquid Crystal Elastomers

et al. 2013

Self Cite

View full text Add to dashboard Cite

Main chain liquid crystal elastomers exhibit several interesting phenomena, such as three different regimes of elastic response, unconventional stress-strain relationship in one of these regimes, and the shape memory effect. Investigations are beginning to reveal relationships between their macroscopic behavior and the nature of domain structure, microscopic smectic phase structure, relaxation mechanism, and sample history. These aspects of liquid crystal elastomers are briefly reviewed followed by a summary of the results of recent elastic and high-resolution X-ray diffraction studies of the shape memory effect and the dynamics of the formation of the smectic-C chevron-like layer structure. A possible route to realizing auxetic effect at molecular level is also discussed.

show abstract

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

Section: Polydomain Smectic-c Main Chain Liquid Crystal Elastomersmentioning

confidence: 99%

See 1 more Smart Citation

Soft Elasticity in Main Chain Liquid Crystal Elastomers

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The curve illustrated here is jagged because the alignment of each domain jumps at a slightly different threshold. The expansion of the film thickness and the energy loss as a result of the jump in the director orientation in this geometry may be observable in experiments on pseudo-monodomains [11,48]. The larger values of deformation reported in experiment before the knee in the stress-strain curve point to a much larger value of α than in the illustrative plot in Fig.…”

Section: Discussionmentioning

confidence: 69%

Negative Poisson's ratio and semisoft elasticity of smectic-Cliquid-crystal elastomers

Brown

Adams

2012

Phys. Rev. E

View full text Add to dashboard Cite

Models of smectic-C liquid-crystal elastomers predict that they can display soft elasticity, in which the shape of the elastomer changes at no energy cost. The amplitude of the soft mode and the accompanying shears are dependent on the orientation of the layer normal and the director with respect to the stretch axis. We demonstrate that in some geometries the director is forced to rotate perpendicular to the stretch axis, causing lateral expansion of the sample-a negative Poisson's ratio. Current models do not include the effect of imperfections that must be present in the physical sample. We investigate the effect of a simple model of these imperfections on the soft modes in monodomain smectic-C elastomers in a variety of geometries. When stretching parallel to the layer normal (with imposed strain) the elastomer has a negative stiffness once the director starts to rotate. We show that this is a result of the negative Poisson's ratio in this geometry through a simple scalar model.

show abstract

“…The small strain induced in the liquid crystal surface agreed with the Poisson's ratio under small strain theory. Therefore, Hookean's law and small strain theory (Poisson's ratio) [20][21] were applied to compute the forces required in inducing the deformation lines in the liquid crystal surfaces. The equation in determining the Young's modulus of a linear elastic material through the relationship of stress-strain established by Hooke's law is as follows:…”

Section: Cell Relaxation Experiments and Quantification Of Cell Tractimentioning

confidence: 99%

Measurement and Mapping of Cell Traction Forces on Liquid Crystal based Force Transducer

Soon¹,

Youseffi²,

Blagden³

et al. 2011

Intelligent Systems and Control / 742: Computational Bioscience

View full text Add to dashboard Cite

A novel cell traction force transducer based on shear sensitive cholesteryl ester liquid crystals (LCTFT) has been developed. This transducer incorporated with a custom-built cell traction force measurement and mapping (CTFM) software showed improved sensitivity and spatial resolution in sensing traction forces of human keratinocytes. The sensing output of the LCTFT was displayed as linear deformation lines in the liquid crystal surface that were induced by contraction of actin filaments via the focal adhesions of cells. In this context, the traction forces that were exerted locally by two clusters of focal adhesions induced strains in bi-axial directions in the liquid crystal surface. By using cell relaxation technique, these strains were determined and they were correlated by Poisson's ratio. With the displacement information, traction forces of single cells were calculated based on Hooke's theorem and the forcedeformation relationships were derived. In this study, the transducer detected a wide range of cell traction forces (~10 -140 nN) indicating the sensitivity of the system. The cell traction force maps generated by our CTFM software at a spatial resolution of ~ 5µm showed good representations of localised cell traction force fields and might be useful for time-based study of dynamic cells tractions.

show abstract

Poisson's Ratio of Monodomain Liquid Crystalline Elastomers

Cited by 49 publications

References 20 publications

Soft Elasticity in Main Chain Liquid Crystal Elastomers

Soft Elasticity in Main Chain Liquid Crystal Elastomers

Negative Poisson's ratio and semisoft elasticity of smectic-Cliquid-crystal elastomers

Measurement and Mapping of Cell Traction Forces on Liquid Crystal based Force Transducer

Contact Info

Product

Resources

About