Spontaneous flow transition in confined active nematic droplets

Active matter collectively organizes mesoscale active stresses that drive a variety of emergent phenomena at the macroscopic scale including spontaneous large-scale, self-driven flows in active nematics. The underlying dynamics of the flows generated in 3D active nematics are thought to be governed by the ratio of nematic elasticity and active stress which sets the active length scale. We find that confining active nematics below a critical length scale stabilizes the dynamics and suppresses flows. This transition between a quiescent and a flowing state is reminiscent of the Fréedericksz transition in equilibrium systems. In this work, we present an analog of the active Fréedericksz transition and probe independently how the interplay between confinement, active stress, and nematic elasticity controls the flow to no-flow transition and investigate the rate of energy consumption in the observed states.