Tuesday, June 12, 2018 4:00 P.M. GCIS W301

Hosted by Women in Chemistry (WiC)
Funded in Part by Student Government

Liquid crystals for self-assembly and optics
Soft materials are a promising tool to explore controllable energy landscapes. Liquid crystals, in particular, combine reconfigurability, unique optical properties and the possibility of directing their self-assembly via the bounding surfaces. These fluids with long-range orientational order possess elastic energy and can generate topological defects, two useful tools for assembly. I will show two examples of interplay between liquid crystal confinement and control of assembly. In one setting, microparticles can be precisely directed to desired locations by modulating the orientation of nematic liquid crystals using topography. An undulated boundary generates small elastic distortions in liquid crystals that can precisely direct the motion of colloidal particles and induce a transformation of the topological defect associated to the particle. In my second example, an array of topological defects in nematic liquid crystals is generated by applying an electric field and it is made regular by appropriate patterning of the electrodes. The defect array can thus form a square lattice of defects, regular over several millimeters, and ideal to create tunable optical gratings.