  The optical properties of liquid crystals serve as the basis for display,
diagnostic, and sensing technologies. Such properties are generally controlled
by relying on electric fields. In this work, we investigate the effects of
microfluidic flows and acoustic fields on the molecular orientation and the
corresponding optical response of nematic liquid crystals. Several previously
unknown structures are identified, which are rationalized in terms of a state
diagram as a function of the strengths of the flow and the acoustic field. The
new structures are interpreted by relying on calculations with a free energy
functional expressed in terms of the tensorial order parameter, using continuum
theory simulations in the Landau-de Gennes framework. Taken together, the
findings presented here offer promise for the development of new systems based
on combinations of sound, flow, and confinement.
