Laser-excited motion of liquid crystals confined in a microsized volume with a free surface.

The thermally excited vortical flow in a microsized liquid crystal (LC) volume with a free LC-air interface has been investigated theoretically based on the nonlinear extension of the Ericksen-Leslie theory, with accounting the entropy balance equation. Analysis of the numerical results show that due to interaction between the gradients of the director field ∇n[over ̂] and temperature field ∇T, caused by the focused heating, the thermally excited vortical fluid flow is maintained in the vicinity of the heat source. Calculations show that the magnitude and direction of the velocity field v, as well as the height of the LC-air interface are influenced by the depth of the heat penetration in the LC volume. It has been shown that there is the point in the vicinity of the LC-air interface where the thermally excited vortical flow changes the direction from anticlockwise to clockwise.