Abstract
Active nematics are out of equilibrium systems that, at the molecular level, consume energy toproduce motion on larger scales. They naturally display turbulence, but controlling this turbulence allows us to modify their behavior. One method of control is by confining them within specific geometries, which necessitates knowledge of how these geometries influence their dynamics. In this dissertation, We used two methods to control the nematic: rigid boundaries and external stimuli. First, we confined the nematic to tame the dynamics using annulus geometry. Varying the annulus’s inner radius and width, we uncover different dynamical states and cluster them using circulation and defect density order parameters. Second, we created a light-activated active nematic using a light-responsive kinesin motor. We characterize the steady-state flow and defect density as a function of applied light. We also examine the transient behavior as the system switches between steady states upon changes in light intensities. Our work establishes an experimental platform that can exploit spatiotemporally- heterogeneous patterns of activity to generate targeted dynamic states.