Controlling an elastic network's structure, mechanics and dynamics with an active fluid*

In vitro experiments have shown that the structure and mechanics of actin networks depend dramatically on both actin and concentration and type of actin crosslinkers. Previous studies have explored networks whose assembly kinetics was driven by thermal motion.  We investigate the behavior of actin networks whose assembly is driven by turbulent-like flows generated by extensile microtubule-kinesin active fluids. Using both widefield and confocal microscopy, we study the structure and dynamics of this composite system across several length and time scales. Our work demonstrates how active fluids can be used to control shape, structure, mechanics and dynamics of elastic filamentous networks.