Spontaneous Flow Transitions in Active Polar Gels

Abstract

Active polar gels are a type of viscoelastic soft material formed by polar filaments which are constantly driven out of equilibrium by the consumption of chemical fuel such as ATP. Following the approach of Voituriez et al, a generic hydrodynamic theory relying on symmetry arguments only was used to study the effects of quasi one-dimensional confinement on active polar gels. The phenomenological theory based on liquid crystal hydrodynamics is motivated by the dynamics of actin filaments in the cytoskeleton which plays an important role in many cellular processes. Using different boundary conditions, Fredericks-like flow transitions driven by the activity are expected. These transitions occur from homogeneously polarized static states in thin gel layers to flowing states with polarization tilts in larger layers. In addition, a few notes on the limitations of this work and possibilities for additional work are briefly expounded on at the end.