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We propose a method for vertical alignment (VA) of liquid crystals (LCs) without alignment layers by mixing only a very low concentration (0.05 wt%) of an organic compound with LCs. The electro-optic characteristics of a VA cell fabricated by the proposed method were almost the same as those of a conventional VA cell with VA layers. Moreover, we used the proposed method to realise a polymer-stabilised VA device with a rapid response time without alignment layers. The proposed method can simplify the fabrication process and reduce the manufacturing cost of LC display devices by removing the need for alignment layers and the alignment process such as coating of polyimide layers and the UV exposure for the photo-alignment. We believe that the proposed method can play an essential role in the fabrication of plastic flexible LC display devices requiring the low-temperature process. [ABSTRACT FROM AUTHOR]

For the fabrication of protrusions in multi-domain vertical alignment liquid crystal displays (MVA-LCDs), a series of complicated and expensive photolithographic processes has to be gone through for the wide viewing angles. In this research, we proposed and demonstrated a new manufacturing approach of the protrusion utilising ink-jet printing technology. Parallel lines were ink-jet printed on the substrates and solidified by a subsequent baking process, and then used as the protrusions of MVA-LCDs. The geometric dimensions of the protrusion patterns were optimised by the comparison of experimental observations and computer simulation results. The MVA-LCD cell was fabricated by arranging the protrusion lines forming right angles between the top and the bottom lines, which resulted in cross-line protrusions. Due to the square-shaped geometric arrangement of the protrusions, the vertically aligned LCs formed the symmetric four-domains in the MVA-LCD cell. With the help of a surface polymer-stabilisation technique, the response time of the LC molecules under the electric field was significantly improved. Therefore, we can conclude that, without sacrificing the viewing angle and response time of MVA-LCD, the printing technique for the formation of the protrusions can give us a new fabrication opportunity with low cost in contrast to the conventional photolithography process. [ABSTRACT FROM PUBLISHER]

A light scatter-free, transparent, thermally stable, optically isotropic liquid crystal mixture was achieved among three different mixtures of liquid crystal E7: Norland Optical Adhesive 65 with concentrations 30:70, 40:60, and 50:50 wt%. The 50:50 wt% mixture exhibited the best performed optically isotropic state when exposed to ultraviolet light of intensity 150 mW/cm 2 for droplet formation. The high intensity ultraviolet light curing process induces nano-sized liquid crystal droplets in the polymer matrix of average droplet size 218 nm, characterized by scanning electron microscope. The analyzed result shows an excellent contrast ratio (CR) equal to 1574 at the normal direction and a high CR at a wide viewing angle. The magnitude of Kerr constant in these nano-sized PDLC was ~7.36×10 −10 mV −2 , which was more than ~330 times that of a conventional Kerr material such as nitrobenzene. Unprecedented fast rising and falling times of approximately 385 µs and 1.1 ms, respectively, were achieved for the device. This high-performance material also eliminated the long-term hurdle of hysteresis to make it a promising candidate for next-generation display and photonic technologies. [ABSTRACT FROM AUTHOR]