Templating flow and topology using liquid crystal microfluidics
By: Anupam Sengupta
From: Max Planck Institut Goettingen
At: Instituto de Investigação Interdisciplinar, Anfiteatro
[2013-10-23]
Flow of molecularly ordered fluids, like liquid crystals, is inherently coupled with the average local orientation of the molecules, or the director. The effective resistance experienced by the flowing matrix depends on the relative orientation between the flow and the director fields. The first part of the talk shall discuss how this anisotropic coupling can be harnessed to pattern different pathways to tunable flow profiles in a microchannel. In contrast to an isotropic fluid, the flow of liquid crystals in microchannels additionally leads to topological constraints in the director field. In the second part of the talk, I shall demonstrate controlled evolution of topological structures of varying effective strengths using microflows. The microfluidic pathway provides a unique tool for engineering defects, and to tune the effective topological strength of the system hierarchically.