Polarization-Dependent Gratings Based on Polymer-Dispersed Liquid Crystal Cells with In-Plane Switching Electrodes

Performances of Polymer-Dispersed Liquid Crystal Films for Smart Glass Applications

Polymer-dispersed liquid crystal (PDLC) film is an active smart film penetrating the market due to its unique functionalities. These functional characteristics include switchable tint capabilities, which shield building residents from the sun's harmful ultraviolet (UV) rays, improve energy-saving features, and produce higher cost-efficiency. Although PDLC films are promising in several applications, there is still ambiguity on the performance of PDLC films. Particularly, the sizing effects' (such as film thickness and area) correlation with visible light transmission (VLT), ultraviolet rejection (UVR), infrared rejection (IRR), light intensity, current consumption, and apparent power consumption is not well understood. Therefore, this study investigated the sizing effects of PDLC films, including the thickness effect on VLT, UVR, IRR, light intensity, and area influence on current and apparent power consumptions. The varying applied voltage effect on the light transmittance of the PDLC film was also effectively demonstrated. A 0.1 mm PDLC film was successfully presented as a cost-efficient film with optimal parameters. Consequently, this study paves the way for a clearer understanding of PDLC films (behavior and sizing effects) in implementing economic PDLC films for large-scale adoption in commercial and residential premises.

Ion-Conducting Composites of Polymers and Nematic Liquid Crystals

In the present mini-review are discussed the findings reported in the last five years on the ion-conducting composites of polymers and molecules of nematic liquid crystals (NLCs), as well as their applications at present and in the future. Nowadays, free-standing and flexible thin films of such organic composite electrolytes synthesized from plastics and nematic soft matter are among the technically important materials and components for use in energy storage and conversion devices and in organic soft electronics, sensorics, and mechatronics. Although the physicochemical mechanisms and effects in the ion-conducting polymer/NLCs composites are well understood, the possibility to find additional ways for improving their electrical conductivity and dielectric and mechanical properties is a challenge. The efforts in this research direction are important for the development of novel ion-conductor materials and further diversification of their applications. This mini-review is focused on the key characteristics of ion-conducting polymer/NLCs composites and the new trends in their fabrication. With relevant examples, the vast research opportunities, some proposed improvements, and the creative ideas associated with these advanced materials and their intelligent use are outlined.

Aerosol jet printing polymer dispersed liquid crystals on highly curved optical surfaces and edges

We demonstrate a new technique for producing Polymer Dispersed Liquid Crystal (PDLC) devices utilising aerosol jet printing (AJP). PDLCs require two substrates to act as scaffold for the Indium Tin Oxide electrodes, which restricts the device geometries. Our approach precludes the requirement for the second substrate by printing the electrode directly onto the surface of the PDLC, which is also printed. The process has the potential to be precursory to the implementation of non-contact printing techniques for a variety of liquid crystal-based devices on non-planar substrates. We report the demonstration of direct deposition of PDLC films onto non-planar optical surfaces, including a functional device printed over the 90° edge of a prism. Scanning Electron Microscopy is used to inspect surface features of the polymer electrodes and the liquid crystal domains in the host polymer. The minimum relaxation time of the PDLC was measured at 1.3 ms with an 800 Hz, 90 V, peak-to-peak (Vpp) applied AC field. Cross-polarised transmission is reduced by up to a factor of 3.9. A transparent/scattering contrast ratio of 1.4 is reported between 0 and 140 V at 100 Hz.