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Articles
by
Shin-Tson Wu |
Total Records (
4 ) for
Shin-Tson Wu |
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Sebastian Gauza
,
Amanda Parish
,
Shin-Tson Wu
,
Anna Spadlo
and
Roman Dabrowski
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We have designed, synthesised and evaluated the physical properties of high-birefringence (Δn) isothiocyanato phenyl-tolane and terphenyl liquid crystals. These compounds exhibit a Δn∼0.36-0.52 at room temperature and wavelength λ = 633 nm. A different mesomorphic sequence was observed depending on the terminal alkyl chain length. Compounds with a longer chain show smectic and nematic phases, whereas short-chain homologues only exhibit a nematic phase. In the vicinity of the nematic-to-smectic transition, the viscoelastic coefficient decreases, instead of increases, as the temperature decreases. The observed change is as large as 75% for the 4`-(3,5-difluoro-4-isothiocyanatophenylethynyl)-4-pentylbiphenyl compound studied. This behaviour is useful for improving the response time of a liquid crystal device, if the operating temperature can be controlled accurately. |
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Haiqing Xianyu
,
Yue Zhao
,
Sebastian Gauza
,
Xiao Liang
and
Shin-Tson Wu
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Some high birefringence ester liquid crystal compounds with cyanate or isothiocyanate polar groups were investigated, the relaxation frequency of which is in the kilo-Hertz region. These compounds are useful for formulating dual-frequency liquid crystal (DFLC) mixtures. The dielectric relaxation and electro-optical properties of these compounds were characterised. Potential applications of these compounds for DFLC mixtures to meet different requirements are discussed. |
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Haiqing Xianyu
,
Shin-Tson Wu
and
Chih-Lung Lin
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We review the recent progress in developing high performance dual frequency liquid crystal (DFLC) materials. A new figure of merit is derived for evaluating the DFLC performance. The dielectric relaxation and electro-optical properties of several high performance compounds, which possess a positive dielectric anisotropy at low frequencies and a relaxation frequency in the kilohertz region, are presented. Potential applications of these compounds are discussed. Compounds with a negative dielectric anisotropy were also compared and discussed. Two experimental DFLC mixtures were demonstrated with one intended for room temperature operation and another for elevated temperature operation. |
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Sukin Yoon
,
Miyoung Kim
,
Min Su Kim
,
Byeong Gyun Kang
,
Mi-Kyung Kim
,
Anoop Kumar Srivastava
,
Seung Hee Lee
,
Zhibing Ge
,
Linghui Rao
,
Sebastian Gauza
and
Shin-Tson Wu
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Liquid crystal displays based on the Kerr effect are emerging because of their attractive features, such as symmetric viewing angle, no need for alignment layer, and sub-millisecond response time. However, high operating voltage and low optical efficiency remain as challenges to be overcome. Here, we propose a new cell structure with a protrusion shape of electrode and a driving scheme using two transistors to reduce operating voltage and enhance light efficiency. Confirming simulation results are obtained. |
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