We successfully fabricated the in-plane switching mode (IPS) LC display (LCD) based on a double stranded DNA (dsDNA) alignment layer. As widely known, the DNA has the right-handed double helical structure that has naturally grown grooves with a very regular period, which can be used as an alignment layer to control the orientation of liquid crystal (LC) molecules. The LC molecules on this topographical layer of DNA material align obliquely at a specific angle with respect to the direction of DNA chains, providing an instant and convenient tool for the fabrication of the IPS display compared to the conventional ways such as rubbing and mechanical shearing methods. The electro-optical performance and response time of this device were also investigated. Our result will be of great use in further exploration of the electro-optical properties of the other biomaterials.

Upon UV irradiation of a bent-core liquid crystal (LC) bearing an azo linkage doped with chiral molecules, a photo-induced transition takes place from BPI to BPIII. BPIII is stabilised over 20 C, while the widening of the BPI range is not so remarkable. The mechanism of photo-induced BPI-BPIII transition is also discussed.

In this study, we investigated the use of biomaterials in optoelectronic applications. One of the most abundant biomaterials in nature is deoxyribonucleic acid (DNA). It was used in this study as an alignment layer to fabricate a twisted-nematic-mode (TN-mode) liquid crystal display (LCD). To create the LCD, a cheap DNA material extracted from salmon was used to coat an indium tin oxide glass substrate, and the DNA chains were aligned with a simple but effective mechanical shearing method at room temperature. Then small rod-type LC molecules were spread on top of the alignment layer, obliquely aligned with respect to the long axis of the DNA chains because of the polar and topographical interactions between the LC molecules and the DNA material. The electro-optical characteristics of the LCD device were examined to compare the properties of the DNA-based LCD with those of a TN-mode LCD fabricated with the conventional rubbed polymer alignment layer. We believe our method provides an easy and useful tool for the fabrication of biomaterial-based optoelectronic devices.

We investigated a controlled helical nanofilament (HNF: B4) phase under topographic confinement with airflow that can induce a shear force and temperature gradient on the sample. The resulting orientation and ordering of the B4 phase in this combinational effort was directly investigated using microscopy. The structural freedom of the complex B7 phase, which is a higher temperature phase than the B4 phase, can result in relatively complex microscopic arrangements of HNFs compared with the B4 phase generated from the simple layer structure of the B2 phase. This interesting chiral/polar nanofilament behaviour offers new opportunities for further exploration of the exotic physical properties of the B4 phase.

No abstract