Nonmechanical pumping principle in submicrosized devices

Abstract

Dynamic field pumping principle has been developed utilizing the interactions of both the director and velocity fields and temperature-redistribution across a two-dimensional (2D) homogeneously aligned liquid crystal (HALC) film under the influence both of a heat flow directed normal to the upper bounding surface, whereas on the lower bounding surface, the temperature is kept constant, and the normally directed electric field, due to electric double layers, i.e., a shielding layers that is naturally created within the liquid crystal (LC) near a charged surfaces. Calculations, based on the nonlinear extension of the classical Ericksen-Leslie theory, shows that the HALC material under the influence of the heat flow start moving in the horizontal direction. After turning off the heat flow, the HALC drop settles down to the rest, and the temperature field across the LC film is finally downfall to the value of temperature on the lower bounding surface. The role of hydrodynamic flow in the relaxation processes of the temperature field to its equilibrium distribution across the 2D HALC film, containing 4-n-pentyl-4(')-cyanobiphenyl, has been investigated for a number of dynamic regimes.