Frequency-controlled dielectrophoresis-driven wetting of nematic liquid crystals

We show that surface-localized dielectrophoresis-driven wetting of anisotropic nematic liquid crystal sessile droplets obeys the same relationship, cos [theta(V-0)] = cos [theta(Y)] - beta V-0(2), which has previously been found for isotropic liquid droplets, even though the nematic liquid crystal phase possesses a uniaxial dielectric permittivity tensor. We also demonstrate that the dielectrowetting coefficient which determines the magnitude of the reduction in the contact angle, from By to theta (V-0), through the action of a potential difference V-0, can be controlled by the frequency of the applied voltage between interdigitated electrodes beneath a droplet of highly dispersive nematic liquid crystal. Our Q-tensor modelling of the electric field-induced 2-dimensional n-director distortions within a nematic droplet elucidates how this linear relationship holds for voltages when vertical bar theta (V-0) - theta(Y)vertical bar exceeds 3 degrees-4 degrees.

Automated summary

It has been found that the wetting of anisotropic nematic liquid crystal sessile droplets follows the same relationship as isotropic liquid droplets. The dielectrowetting coefficient, which determines the reduction in the contact angle, can be controlled by the frequency of the applied voltage.