Observation of liquid crystals confined in an elliptic cylinder

Abstract

We present the observation of liquid crystals confined in elliptic cylinders. To fabricate the elliptic cylinder, poly(dimethlysiloxane) micro-channels having circular cross sections are stretched uniaxially along the direction of the diameter. Upon increasing the aspect ratio of the elliptic cross section, confined nematic liquid crystals maintain their escaped-radial configuration with homeotropic anchoring. In smectic-A liquid crystals, defect regions of focal conic domains appear as a function of the aspect ratio. We propose a model to understand the formation of these defects in terms of the confinement-induced misorientation, and resultant tilt grain boundaries. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4745773]