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Bistable nematic liquid crystal device with flexoelectric switching



Motivated generally by potential applications in the liquid crystal display industry [8,35], and specifically by recent experimental, theoretical and numerical work [6,7,13,14,21,25,30,31], we consider a thin film of nematic liquid crystal (NLC), sandwiched between two parallel plates. Under certain simplifying assumptions, laid out in £2, we find that for monostable surfaces (i.e. only a single preferred director anchoring angle at each surface), two optically-distinct, steady, stable (equal energy) configurations of the director are achievable, that is, a bistable device. Moreover, it is found that the stability of both of these steady states may be destroyed by the application of a sufficiently large electric field, and that switching between the two states is possible, via the flexoelectric effect. Such a phenomenon could be used in NLC display devices, to reduce power consumption drastically. Previous theoretical demonstrations of such (switchable) bistable devices have either relied on having bistable bounding surfaces, that is, surfaces at which there are two preferred director orientations at the surface [7,14]; on having special (nonplanar) surface morphology within the cell that allows for two stable states (the zenithal bistable device (ZBD) [4,21], or, in the case of the Nemoptic BiNem technology [11,19], on flow effects and a very carefully applied electric field to effect the switching.<br/><br/

Year: 2006
OAI identifier: oai:eprints.soton.ac.uk:156359
Provided by: e-Prints Soton

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  1. (n.d.) Azimuthal anchoring of nematic on undulated substrate: Elasticity versus memory. http://www.nemoptic.com/binem/publications.htm doi
  2. (n.d.) Bistable nematic liquid crystal device. doi
  3. (n.d.) Bistable nematic liquid crystal display device. doi
  4. (n.d.) New bistable nematic LCDs using a weak anchoring boundary. http://www.nemoptic.com/binem/publications.htm
  5. (2001). A novel approach to modelling nematic liquid crystal cells. doi
  6. (1985). A novel method for determining the anchoring energy function at a nematic liquid crystal-wall interface from director distortions at high fields. doi
  7. (2000). Anchoring strength and high pretilt angle in NLC on rubbed organic solvent soluble polyimide surfaces with trifluoromethyl moieties. doi
  8. (2001). Bistable nematic liquid crystal device. doi
  9. (2002). D a v i d s o n ,A .J .&M o t t r a m doi
  10. (1998). D o e d e l ,E .J . ,C h a m p n e y s ,A .R . ,F a i r g r i e v e ,T .F . ,K u z n e t s o v ,Y u .A . ,S a n d s t e d e ,B doi
  11. (2002). Deformation of nematic liquid crystals in an electric field. doi
  12. E r i c k s e n ,J .L .(1960) Anisotropic Fluids. doi
  13. (2001). Flexoelectric surface switching of bistable nematic devices. doi
  14. (1999). Generation of high pretilt angle and surface anchoring strength in nematic liquid crystal on a rubbed polymer surface. doi
  15. (1999). Influence of guest conformation (rod- or banana-like photo-isomers) on flexoelectric coefficients in nematic liquid crystals. doi
  16. (2004). Influence of the ions on the dynamical response of a nematic cell submitted to a dc voltage. doi
  17. (1989). Invited Lecture: Experimental studies of the anchoring energy of nematic liquid crystals. doi
  18. J i n ,W . ,L i u ,Y . ,X i e ,P . ,Z h a n g ,R . ,Z h u ,C .&W a n g ,C .(1999) A combined method based on rubbing and UV-irradiation for preparing stable alignment layers with high pretilt angles. doi
  19. (1998). K e d n e y doi
  20. L e s l i e ,F .M .(1966) Some constitutive equations for anisotropic fluids. doi
  21. L e s l i e ,F .M .(1968) Some constitutive equations for liquid crystals. doi
  22. (2001). Liquid crystal optical rotator using weak azimuthal anchoring surface. doi
  23. M a d a ,H .&S a t o ,S .(1999) Pretilt angle dependence of azimuthal anchoring energy in nematic liquid crystals. doi
  24. (1996). Magnetic field-mediated alignment of a nematic liquid crystal at a polymer surface exposed to ultraviolet light. doi
  25. (2003). Measurement of genuine azimuthal anchoring energy in consideration of liquid crystal molecular adsorption on alignment film. doi
  26. (2000). Photoinduced surface alignment for liquid crystal displays. doi
  27. R a p i n i ,A .&P a p o u l a r ,M .(1969) Distorsion d’une lamelle n´ ematique sous champ magn´ etique. Conditions d’ancrage aux parois. doi
  28. R y s c h e n k o w ,G .&K l e m a n ,M .(1976) Surface defects and structural transitions in very low anchoring energy nematic thin films. doi
  29. (1992). Relationship between rubbing strength and surface anchoring of nematic liquid crystal. doi
  30. (1997). S l a v i n e c ,M . ,C r a w f o r d ,G .D . ,K r a l j doi
  31. (2002). Structures and properties of liquid crystals and related molecules from computer simulation.
  32. (2004). The Static and Dynamic Continuum Theory of Liquid Crystals. doi
  33. (1979). Theory of flow phenomena in liquid crystals. doi
  34. (2003). Tilt angle generation for nematic liquid crystal on blended homeotropic polyimide layer containing Trifluoromethyl moieties. doi
  35. (1994). U.S. Patent no. 5,357,358 doi
  36. V i l f a n ,M .&C o p i c ,M .(2003) Azimuthal and zenithal anchoring of nematic liquid crystals. Phys Rev. doi

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