Wetting and Microfluidic Flow of Liquid Crystal Droplets

点击翻译按钮获取中文摘要

Liquid crystals (LCs) are fascinating materials as they feature properties between those of simple liquids and solid crystals. They have been often referred to as the fourth state of matter and ushered in a technological revolution due to their unique capability of modulating visible light. The potential for technological applications is far from being exhausted as new areas emerge constantly, such as LC-based integrated lab-on-a-chip devices, micro- and optofluidic systems as well as biosensors.In this project we want to investigate the flow and wetting behaviour of liquid crystalline droplets [1] close to functional surfaces and in micrometre-sized flow geometries. It will be carried out in a collaboration between the Department of Physics and the Department of Mathematics and Statistics at the University of Strathclyde and use a combination of computational methods such as the lattice-Boltzmann method for fluid dynamics and free energy functional methods [2] and analytical theory like the Leslie-Ericksen framework [3]. The outcome will be interesting from a fundamental point of view of liquid crystal physics, but be also highly relevant for ink-jet printing processes that will form a cornerstone of new manufacturing methods for the next generation of liquid crystal displays.Some of the key research directions include the study of topological defects in droplets in flight or in suspended droplets, a very active field of current liquid crystal research, but entirely unexplored in its dependence of flow and wetting behaviour. Other directions comprise the impact of droplets on functional substrates and the in-flight annealing of defects as well as the equilibrium shape and order structure of droplets.[1] M. Urbanski, C.G. Reyes, J.H. Noh, A. Sharma, Y. Geng, V.S. Jampani and J.P. Lagerwall, J. Phys. Condens. Matter 29, 133003 (2017).[2] K. Stratford, O. Henrich, J. Lintuvuori, D. Marenduzzo, M.E. Cates, Self-Assembly of Colloid- Cholesteric Composites: A Route to Switchable Optical Materials, Nat. Comm. 5, 3954 (2014).[3] P.G. de Gennes, J. Prost, The Physics of Liquid Crystals, Oxford University Press, 2nd editon (2002).