Georgy Kitavtsev: Modelling cell motility as an active liquid crystal film with moving free boundaries

In this talk, I model the complex problem of description of cell motility as the Adenosinetriphosphate (ATP) driven motion of a thin film of an actin filament network.
This model is based on the Beris-Edwards theory that uses a tensorial order parameter that includes active contributions to the stress tensor. The small aspect ratio of the film geometry allows for an asymptotic approximation of the free-boundary problem in the limit of weak elasticity of the network and strong active terms. The new thin film model captures the defect dynamics in the bulk as well as wall defects and thus presents a significant extension of previous models based on the Lesli-Erickson-Parodi theory. Analytic expressions are derived that reveal the interplay of anchoring conditions, film thickness and active terms and their control of transitions of flow structure.