• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.8
• /
• pp.700-703
• /
• 2000

We investigated the improvement using a new patterned double twisted(PDT) vertical-alignment(VA) cell mode on a homeotropic alignment layer. Good voltage-transmittance curves for negative dielectric anisotropic nematic liquid crystal (NLC) using a new PDT-VA cell without a negative compensation film were obtained. The viewing angle of a new PDT-VA cell without a negative compensation film was sider than that of a conventional VA cell. Finally a few fabrication processes using a new PDT-VA cell mode can be achieved by only one-side rubbed substrate.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.645-647
• /
• 2009

We investigated vertical liquid crystal (LC) alignment effects of a self-assembled-monolayer (SAM) prepared on an anisotropic $SiO_2$ surface where the field-induced LC reorientation produced a uniform single domain texture. We compared the results with the homeotropic-to-random planar reorientation results shown in LCs aligned on a SAM surface prepared on an isotropic $SiO_2$ surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.10
• /
• pp.883-886
• /
• 2000

We have developed a novel vertical-alignment(VA) - 1/6$\pi$ mode that provides a wide viewing angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on a homeotropic polyimide (PI) surfaces. Good voltage-transmittance curves were achieved with the new VA - 1/6$\pi$ cell model without a negative compensation film. The viewing angle of a new VA -1/6$\pi$ cell without a negative compensation film was wider than that of a conventional VA cell. Finally, the wide viewing angle using the new VA-1/6$\pi$ cell mode can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.62-65
• /
• 2005

We studied the nematic liquid crystal (NLC) alignment capability by the Ultraviolet (UV) alignment method on a-C:H thin-films, and investigated electro-optical performances of the UV aligned twisted nematic (TN)-liquid crystal display (LCD) with the UV exposure on a-C:H thin film surface. A good LC alignment by UV irradiation on a-C:H thin-film surfaces was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. The good electro-optical (EO) characteristics of the UV aligned TN-LCD was observed with oblique UV exposure on the a-C:H thin film surface for 1min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.378-378
• /
• 2007

In this study, liquid crystal (LC) aligning capabilities for homeotropic alignment on the $ZrO_x$ thin film by electron beam evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the NLC treated on $ZrO_x$ thin film were investigated. The uniform LC alignment on the $ZrO_x$ thin film surfaces and good thermal stabilities with electron beam evaporation can be achieved. It is considerated that the LC alignment on the $ZrO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $ZrO_x$ thin film surface created by evaporation. In addition, it can be achieved the good electro-optical (EO) properties of the VA-LCD on $ZrO_x$ thin film layer with. oblique electron beam evaporation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.5
• /
• pp.536-540
• /
• 2004

A novel nematic liquid crystal (LC) cell with splay structure exhibiting wide viewing angle, fast response time and high transmittance at the same time has been developed. With rubbed homeotropic alignment in parallel directions, the device shows bend alignment in the absence of vertical electric field. However, with applied high voltage in a pulse form, the LC shows a optically compensated splay (OCS) orientation such that the mid-director is parallel to a substrate and at both surfaces the LCs are aligned vertically in parallel direction. In the device, the birefringence of the cell becomes tunable with applying voltage, i.e., the amount of light passed through the cell can be controlled by controlling the orientation of the LC. Since the OCS cell has a self-compensation structure such that the LC has a mirror symmetry along the mid-director, the device shows a wide viewing angle with only a single domain and a fast response time.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.4
• /
• pp.332-336
• /
• 2000

We have developed a novel vertical-alignment(VA) -$\pi$ cell mode that provides a wide viewing angle and fast response times for nematic liquid crystal(NLC) with negative dielectric anisotropy on a homeotropic polymide(PI) surfaces. Good voltage-transmittance curves and low driving voltages were achieved with the new VA-$\pi$ cell mode without a negative compensation film. Iso-viewing angle characteristics using the new VA-$\pi$ cell mode without a negative compensation film was also successfully observed. As well a fast response time of 31.7 ms for a new VA-$\pi$ mode was measured. Consequently the iso-viewing angel fast response time and low driving voltage characteristics using a VA-$\pi$ cell can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.549-552
• /
• 1999

We have developed an novel vertical-alignment (VA) - $\pi$ cell mode that provides a wide viewing angle and fast response times for negative dielectric anisotropy nematic liquid crystal (NLC) on a homeotropic polyimide (PI) surfaces. We had the good voltage-transmittance curves and low driving voltages were achieved with the novel VA - $\pi$ cell mode without negative compensation film. Iso-viewing angle characteristics using the novel VA - $\pi$ cell mode without negative compensation film of NLC was also successfully observed. As well a fast response time of 31.7ms for the novel VA - $\pi$ cell mode was measured. Consequently, It is seen that by using the novel VA - $\pi$ cell mode the iso-viewing angle, fast response time, and low driving voltage characteristics can be achieved.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1262-1266
• /
• 2010

In this study, we investigated the use of liquid crystals to selectively detect the activity of enzymes at interfaces decorated with oligopeptide-based membranes. We prepared a mixed monolayer of tetra(ethylene glycol)-terminated lipids and carboxylic acid-terminated lipids at the aqueous-liquid crystal (LC) interface. The 17 amino-acid oligopeptide SNFKTIYDEANQFATYK was then immobilized onto this mixed monolayer through N-hydroxysuccinimide-activation of the carboxylic acid groups. We examined the orientational behavior of nematic 4-cyano-4'-pentylbiphenyl (5CB) after conjugation of the 17 amino-acid oligopeptide with the mixed monolayer assembled at the interface. Immobilization of the oligopeptide caused orientational transitions in 5CB, with a change from homeotropic (perpendicular) to tilted alignment, which was primarily due to the reorganization of the monolayer. The orientation of the 5CB molecules returned to its homeotropic state after contacting the interface containing ${\alpha}$-chymotrypsin, which can cleave the immobilized oligopeptide. Control experiments confirmed that the enzymatic activity of ${\alpha}$-chymotrypsin triggered the ordering transitions in the LC. These results suggest that the LC can provide a facile method for selective detection of enzymatic activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.189-192
• /
• 2005

We have investigated the EO characteristics generation of pretilt angle for a nematic liquid crystal (NLC) alignment with photoalignment method on three kinds of photopolymer surfaces using polymer substrates. The LC homogeneous alignment were observed on the PMI3CA (N-(phenyl)maleimide with 3-carbon chain cinnamoyl group) and PMIF (N-(phenyl)maleimide including fluoro cinnamoyl group). However, the homeotropic alignment on the PMI5CA(N-(phenyl)maleimide with 5-carbon chain cinnamoyl group) was obtained. Also, EO characteristics of the flexible photoaligned TN-LCD using PMIF surface are better than that of the flexible TN-LCD using PMI3CA surface. Also, the stable EO performances of flexible photoaligned VA-LCD using the PMI5CA surface was observed.