Dr. Francesca Serra 

 

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. I will show, for example, how smectic-A liquid crystals under different boundary conditions create microlens arrays made of focal conic defects or light guides in an aqueous solution. Focal conic domains act as gradient refractive index lenses that can be assembled and ordered exploiting topographical cues. The smectic light guides, floating in water, can be induced to align along grooves or wrinkles in the substrate without the need for external manipulation. Finally, microparticles can be precisely directed to desired locations by modulating the director field of nematic liquid crystals through topography.