Linear elasticity of polymer gels in terms of negative energy elasticity

Anomalous elasticity of polymer cholesterics.

We show that polymer cholesterics have much longer pitches than comparable short molecule cholesterics, due to their anomalous elasticity. The pitch P of a chiral mixture with concentration c near the racemic (non-chiral) concentration c diverges like |c− c∗|−ν with, according to our very precise calculations [1], ν = 1.43 ± 0.04 (for short molecule cholesterics ν = 1). The short molecule law i...

Alignment and nonlinear elasticity in biopolymer gels.

We present a Landau-type theory for the nonlinear elasticity of biopolymer gels with a part of the order parameter describing induced nematic order of fibers in the gel. We attribute the nonlinear elastic behavior of these materials to fiber alignment induced by strain. We suggest an application to contact guidance of cell motility in tissue. We compare our theory to simulation of a disordered ...

En224: Linear Elasticity

On the Elasticity of Stiff Polymer Networks

The mechanical properties of cytoskeletal actin bundles play an essential role in numerous physiological processes including hearing, fertilization, cell migration and growth. Cells employ a multitude of actin-binding proteins to regulate actively bundle dimensions and crosslinking properties to suit biological function. The mechanical properties of actin bundles vary by orders of magnitude dep...

The Elasticity of Elasticity

In this talk I assert that the usual interpretation of what one means by “elasticity” is much too insular and illustrate my thesis by introducing implicit constitutive theories that can describe the nondissipative response of solids. I show that response which was hitherto untenable within the context of Cauchy or Green Elasticity are not only possible, they can explain phenomena that have thus...