Manipulating the Resistivity of Molecular Liquid Crystals

Numerous applications of molecular liquid crystals including displays and tunable electro-optical components (filters, waveplates, waveguides, light modulators, etc.) rely on high resistivity mesogenic materials. There are also applications such as privacy windows and light shutters taking advantage of the dynamic light scattering effect where ions are required for proper performance. Therefore, the control over the resistivity of molecular liquid crystals is of utmost importance. While it is relatively easy to change the resistivity of molecular liquid crystals by 2-3 times, a change of several orders of magnitude in the resistivity is not a trivial task. In our research, we discuss the possibility to control (either increase or decrease) the resistivity of molecular liquid crystals by several (2-4) orders of magnitude using nanomaterials. The adsorption effect of nanoparticles can increase or decrease the ion contamination, therefore the resistivity. The use of nano-dopants may improve the performance of liquid crystal devices including LCDs, electrically controlled lenses, and tunable optical elements such as smart windows and microwave devices. We analyze how the type of nanoparticles, their concentration, their size, and the level of ionic contamination affect the electrical resistivity of molecular liquid crystals in a desirable way.