Channel confined active nematics

Active nematics is a popular model fluid for active matter. The popularity comes from the fact that several biological systems involving cells and cytoskeletal elements closely match active nematic fluid. Moreover, the theory of active nematics is amenable for analytical and computational developments. This review discusses different flow states and flow transitions exhibited by channel confined active nematics. The discussions based on experimental and theoretical investigations reveal the role of inherent hydrodynamic instabilities, the unique fluid properties, and the bounding geometry in dictating the behavior of active nematic fluids in channel confinements. The discussions also highlight the current and outstanding research questions in the field.