Laser-driven nematic flow in microfluidic devices

Based on a nonlinear extension of the Ericksen-Leslie theory, taking into account the entropy balance equation, a theoretical study of a thermally excited vortex flow in a microsized hybrid-aligned nematic (HAN) volume was carried out. Analysis of the numerical results show that due to interaction between the gradients of the director field ∇n[over ̂] and temperature ∇T, caused by the focused laser radiation, the thermally excited vortical fluid flow is maintained in the bulk of the HAN channel. Calculations have shown that the features of the vortex flow are influenced not only by the direction of the heat flux relative to the bounding surfaces, but also by the orientational defect on these surfaces.