Modelling a planar bistable device on different scales

47 mins 31 secs,  181.77 MB,  iPod Video  480x270,  29.97 fps,  44100 Hz,  522.3 kbits/sec
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Description: Majumdar, A (University of Bath)
Tuesday 19 March 2013, 09:50-10:40
 
Created: 2013-03-19 14:19
Collection: The Mathematics of Liquid Crystals
Publisher: Isaac Newton Institute
Copyright: Majumdar, A
Language: eng (English)
Distribution: World     (downloadable)
Explicit content: No
Aspect Ratio: 16:9
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: This talk focuses on the development, analysis and numerical implementation of mathematical models for a planar bistable nematic device reported in a paper by Tsakonas, Davidson, Brown and Mottram. We model this device within a continuum Landau-de Gennes framework and investigate the cases of strong and weak anchoring separately. In both cases, we find six distinct states and compute bifurcation diagrams as a function of the anchoring strength. We introduce the concept of an optimal boundary condition that prescribes the optimal interpolation between defects at the vertices. We develop a parallel lattice-based Landau-de Gennes interaction potential, by analogy with the Lebwohl-Lasher lattice-based model and study multistability within this discrete framework too by means of Monte Carlo methods. We also use the off-lattice based Gay Berne model to study the structure of the stable states. The different numerical approaches are compared and we discuss their relative strengths a nd shortcomings. We conclude by a brief discussion on a multiscale modelling approach wherein we can couple a lattice-based interaction potential to a conventional continuum model. This is joint work with Chong Luo and Radek Erban.
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