Nematic electric field effects

Electric field effects have been studied in cholesteric liquid crystals by Muller (17) and Harper (9). Since the structure for this phase is different from the nematic phase, their work and the work discussed in this article cannot be compared at this time. 

Electric field effects are more complicated because of conduction. The Carr-Helfrich instability, which occurs in nematics of negative dielectric anisotropy (see 3.10.2), may be expected to take place in this case too, only the bend and twist distortions are now coupled. Moreover, the fluid motion along z can occur only by the process of permeation ( 4.5.1). 

Optics and Electric Field Effects in Nematic and Smectic A Liquid Crystals... 

In conclusion, electric field effects in liquid crystals is a well-developed branch of condensed matter physics. The field behavior of nematic liquid crystals in the bulk is well understood. To a certain extent the same is true for the cholesteric mesophase, although the discovery of bistability phenomena and field effects in blue phases opened up new fundamental problems to be solved. Ferroelectric and antiferroelectric mesophases in chiral compounds are a subject of current study. The other ferroelectric substances, such as discotic and lyotropic chiral systems and some achiral (like polyphilic) meso-genes, should attract more attention in the near future. The same is true for a variety of polymer ferroelectric substances, including elastomers. 

FAST SWITCHING OF NEMATIC LIQUID CRYSTALS BY AN ELECTRIC FIELD EFFECTS OF DIELECTRIC RELAXATION ON THE DIRECTOR AND THERMAL DYNAMICS... 

It should be mentioned that Fraser [92] has carried out a theoretical investigation of the twisted nematic device that incorporates surface pretilt of the director and electric field effects. Much of the analysis is naturally extended from the ideas presented on pretilt in Section 3.4.2 and electric field effects in Section 3.5. 

---