Consequences of director-density coupling theory for flexoelectricity in nematic liquid crystals

We theoretically study how the measurements of the flexoelectric coefficients in nematic liquid crystals are affected by the inclusion of the director-density coupling energy. It is shown that this investigation is quite relevant for interpreting the data of experiments.

Figure 1

Cell of thickness $h$ containing a nematic liquid crystal: (a) Homeotropic alignment and (b) planar alignment. On the right, the coordinate system defines the angle $\theta$ for the director.

Figure 2

Twisted nematic cell of thickness $h$. On the right, the coordinate system defines the angles $\theta$ and $\varphi$ for the director.