A planar bistable liquid crystal device, reported in Tsakonas, is modeled within the Landau-de Gennes theory for nematic liquid crystals. This planar device consists of an array of square micrometer-sized wells. We obtain six different classes of equilibrium profiles and these profiles are classified as diagonal or rotated solutions. In the strong anchoring case, we propose a Dirichlet boundary condition that mimics the experimentally imposed tangent boundary conditions. In the weak anchoring case, we present a suitable surface energy and study the multiplicity of solutions as a function of the anchoring strength. We find that diagonal solutions exist for all values of the anchoring strength W≥0, while rotated solutions only exist for W≥W c>0, where W c is a critical anchoring strength that has been computed numerically. We propose a dynamic model for the switching mechanisms based on only dielectric effects. For sufficiently strong external electric fields, we numerically demonstrate diagonal-to-rotated and rotated-to-diagonal switching by allowing for variable anchoring strength across the domain boundary. © 2012 American Physical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-C1-013-04
Acknowledgements: We thank Professor Nigel Mottram and Dr. Peter Howell for helpful discussions. This publication was based on work supported in part by Award No KUK-C1-013-04, made by King Abdullah University of Science and Technology (KAUST). A.M.'s research is also supported by an EPSRC Career Acceleration Fellowship No. EP/J001686/1. The research leading to these results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 239870. R.E. would also like to thank Somerville College, University of Oxford, support from a Fulford Junior Research Fellowship; Brasenose College, University of Oxford, support from a Nicholas Kurti Junior Fellowship; the Royal Society support from a University Research Fellowship, and the Leverhulme Trust for support from a Philip Leverhulme Prize.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.