The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Electric field induced deformations of chiral nematic liquid crystal layers were studied numerically. Uniformly lying helix structure of short pitch flexoelectric mixtures was considered. The electro-optic effect due to rotation of optical axis around the normal to the layer was simulated. The flexoelectric torque arising under the action of bias voltage and responsible for this rotation was calculated...
The small deformations induced by electric field in twisted flexoelectric nematic layers were simulated numerically. The onedimensional (i.e. homogeneous over the whole area of the layer) and two-dimensional (i.e. spatially periodic flexoelectric domains) deformations were considered. It was shown that the periodic deformations do not arise if sufficiently high pretilt angle is imposed by the boundary...
Electric field induced deformations occurring in twisted nematic cells filled with liquid crystalline material possessing flexoelectric properties were simulated numerically. The aim of computations was to compare the two-dimensional periodic deformations with one-dimensional distortions reported in our earlier paper occurring in the same cells. It was found that the periodically deformed structures...
Formulae used for description of anchoring energy of nematic liquid crystal aligned on solid substrates are reviewed. They are based on macroscopic approach considering the concepts of the easy axis and of the anchoring strength parameters. Properties of the modified formula proposed in our earlier article are illustrated by exemplary plots which allows for comparison with other formulae. The modified...
Dynamics of DC electric field induced deformations of flexoelectric nematic layers were studied numerically. The characteristic response times were calculated. It was found that the cooperative effect of flexoelectricity and of ionic space charge may affect the dynamics of the deformations even in the case of rigid anchoring.
Deformations of nematic layers induced by d.c. electric field were studied numerically. The nematic liquid crystal under consideration possessed flexoelectric properties. Its dielectric anisotropy was zero, so the deformations were solely of flexoeleclric nature. The threshold voltages for deformations were calculated for nematics with very low, moderate and high ion content. In the case of weak flexoelectric...
The deformations of homeotropic nematic layers induced by ac electric field of frequency f were studied numerically. Two kinds of nematic liquid crystals with small negative dielectric anisotropy, Δε < 0, were considered: (i) the non-flexoelectric nematic, (ii) the nematic characterised by the positive sum of flexoelearic coefficients e = e11 + e33 > 0. It was found that at sufficiently low...
Deformations of nematic layers induced by electric field were studied numerically. The role of very strong flexoelectric properties was considered. The threshold voltages for deformations were calculated for nematics with very low, moderate and high ion contents and characterized by negative dielectric anisotropy. The director distributions were also determined. When the sum of flexoelectric coefficients...
Elastic deformations of homeotropic nematic liquid crystal layers subjected to a d.c. electric field were studied numerically. The flexoelectric properties of the nematic material and the presence of ionic space charge were taken into account. The influence of anchoring strength W was investigated. The calculations were performed for layers with negative dielectric anisotropy and negative sum of flexoelectric...
Numerical studies of d.c. electric field induced deformations of homeotropic layers of flexoelectric nematics containing ions are presented. It is shown that anomalous dependencies of threshold voltage for deformations on ion concentration, which were found in our previous papers, are due to difference between mobilities of cations μ + and anions μ -. The influence of this difference on the deformations...
Deformations of planar nematic layers of conducting nematic liquid crystal possessing flexoelectric properties and subjected to external d.c. voltage were studied numerically. Various kinds of electrodes, from strongly blocking to well conducting, were assumed. The calculations were performed for nematic material characterized by positive dielectric anisotropy and by positive sum of flexoelectric...
Homeotropic layer of conducting nematic liquid crystal possessing flexoelectric properties and subjected to external d.c. voltage was studied numerically. The strongly blocking electrodes were assumed. The calculations were performed for four types of nematic materials characterized by both signs of dielectric anisotropy and by both signs of the sum of flexoelectric coefficients. The thresold voltages...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.