Buckling Instability in 3D Active Nematics

Networks of biopolymers and motor proteins are useful model systems for the understanding of emergent behaviours of active matter. In this study we investigate how this active filamentous structures promote nonequilibrium processes induced by active stress at the microscale. By combining passive processes that produce entropic forces and extensile and contractile forces exerted by motors we show that the system exhibits a nematic organization characterised by long-range orientational order. The evolution of the system over time is particularly interesting and unique. We observe 3D to 2D transition by contracting into a sheet, expansion in the direction perpendicular to the contraction, 3D wrinkling pattern formation, and finally, explosion into a spatio-temporal disordered state. Finally, we examine the influence of external stimuli such as confinement, crowding agent and filament length on the properties of the different development phases of the system.