Physics Colloquium: Elasticity on the edge of stability: soft matter physics inspired by the cell

Abstract:

Much like the bones in our bodies, the cytoskeleton consisting of stiff protein biopolymers determines the mechanical stability and response of cells. Filamentous protein networks also form the basis of extracellular matrices and tissues. Inspired by such filamentous assemblies, we describe recent theoretical modeling and experiments on simplified fiber networks in vitro. Among the more striking material properties of these networks is their nonlinear elasticity. We also show that these exhibit a unique state of highly responsive matter near the isostatic point first studied by Maxwell in the context of particles interacting via central forces. For fiber networks, this represents a marginal state of matter with exceptional mechanical properties,
including a strongly nonlinear response to stress. In fact, such systems exhibit rich zero-temperature critical behavior.

Seminar Organisers: Dr. Tomer Volansky, Dr. Dovi Poznanski