MSE Seminar Series: Francesca Serra, John Hopkins U.
Friday, October 19, 2018
2108 Chem/Nuc (bldg #90)
Title: Control of topological defects and particles in liquid crystals
Speaker: Francesca Serra, Asst Prof @ Johns Hopkins University
Soft materials are a promising tool to explore energy landscapes and to search for new and tunable optical components. Liquid crystals, in particular, combine reconfigurability and unique optical properties, and their order can be controlled by combining appropriate bounding surfaces and external fields. These fluids with long-range orientational order possess elastic energy and can generate topological defects, which can be used for assembly. I will show a few examples of unexpected phenomena generated by the interplay between confinement, liquid crystal elasticity and external fields. Metastable configurations can be induced in thin capillaries filled with liquid crystals. Also, the motion of micro-particles floating in nematic liquid crystals can be precisely directed by small deformations of the boundaries, which can also manipulate the defects near the particles. Finally, the interplay between confinement and electric field leads to the production of highly controlled, large-scale arrays of topological defects that work as tunable optical gratings.
Francesca Serra got her PhD degree in physics at the University of Cambridge. She was then a post-doctoral researcher at the University of Milan and at the University of Pennsylvania, and a visiting scholar at Kyoto university. In 2017 she joined the Physics and Astronomy department at Johns Hopkins University where she is an assistant professor. Her research field is experimental soft matter physics, focusing on the study of liquid crystalline materials.