Electro-optic response of polymer-stabilized blue phase liquid crystals

Xu, Duanfu; Yan, Jin; Yuan, Jiamin; Peng, Fenglin; Chen, Yuan; Wu, Shin‐Tson

doi:10.1063/1.4890031

Cited by 61 publications

(44 citation statements)

References 27 publications

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“…There are several solutions that have been identified to lower the operating voltage [45–47] and make hysteresis free BPLC devices [39, 48–51]. For example, modifications to the device structure have been proposed, such as the planar in plane switching (IPS) structure [52], interdigitated indium tin oxide (ITO) electrodes [53], the protrusion electrode structure [54], periodic corrugated electrodes [36], double-side in plane switching (DS-IPS) [44], and vertical field switching (VFS) [55].…”

Section: Introductionmentioning

confidence: 99%

Blue phase liquid crystal: strategies for phase stabilization and device development

Rahman

Said

Balamurugan

2015

Science and Technology of Advanced Materials

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The blue phase liquid crystal (BPLC) is a highly ordered liquid crystal (LC) phase found very close to the LC–isotropic transition. The BPLC has demonstrated potential in next-generation display and photonic technology due to its exceptional properties such as sub-millisecond response time and wide viewing angle. However, BPLC is stable in a very small temperature range (0.5–1 °C) and its driving voltage is very high (∼100 V). To overcome these challenges recent research has focused on solutions which incorporate polymers or nanoparticles into the blue phase to widen the temperature range from around few °C to potentially more than 60 °C. In order to reduce the driving voltage, strategies have been attempted by modifying the device structure by introducing protrusion or corrugated electrodes and vertical field switching mechanism has been proposed. In this paper the effectiveness of the proposed solution will be discussed, in order to assess the potential of BPLC in display technology and beyond.

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Section: Introductionmentioning

confidence: 99%

Blue phase liquid crystal: strategies for phase stabilization and device development

Rahman

Said

Balamurugan

2015

Science and Technology of Advanced Materials

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“…From previous study, it was found that the severity of electrostriction mainly depends on the soundness of polymer network. 31 Hence, by controlling the UV polarization axis with respect to the direction of the stripe electrodes of an IPS-BPLC cell, the formed anisotropic polymer network could result in anisotropic electrostriction correspondingly. In our experiments, we employed a large Δε nematic LC host JC-BP07N (JNC, Japan) whose physical properties are: Δn = 0.162 at λ = 633 nm, Δε = 302 at 100 Hz and 22°C, and T c = 87˚C.…”

Section: Methodsmentioning

confidence: 99%

“…The fitted time constants and the contribution of electrostriction effect, which is described by B/(A + B) in our model, are also included in Table 1. 31 All the values of t 1 lie in the submillisecond range while those of t 2 are around several milliseconds. These results correspond well with the previously reported response time of fast Kerr effect and the slow electrostriction effect.…”

Section: Dynamic Responsementioning

confidence: 97%

“…To explain the difference, the double relaxation model was used to characterize the decay process. 31 Voltage (V) 60 The fitting curve (magenta solid line) in Fig. 5 indicates that Eq.…”

Section: Dynamic Responsementioning

confidence: 98%

“…As mentioned above, the electrostriction effect causes noticeable hysteresis and increased response time. 31 Accordingly, in order to evaluate the degree of electrostriction, we measured and compared the hysteresis as well as response time of these three samples. The hysteresis was measured by increasing the voltage to their individual peak transmittance and then sweeping it back to zero.…”

Section: Effect Of Uv Polarizationmentioning

confidence: 99%

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Stabilizing blue phase liquid crystals with linearly polarized UV light

Yuan

Schadt³

et al. 2015

SPIE Proceedings

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Polymer-stabilized blue-phase liquid crystal (PS-BPLC) has become an increasingly important technology trend for information display and photonic applications. BPLC exhibits several attractive features, such as reasonably wide temperature range, submillisecond gray-to-gray response time, no need for alignment layer, optically isotropic voltageoff state, and large cell gap tolerance when an in-plane switching (IPS) cell is employed. However, some bottlenecks such as high operation voltage, relatively low transmittance, and noticeable hysteresis and prolonged response time at high field region for IPS mode, still remain to be overcome before widespread application of BPLC can be realized. To reduce operation voltage, both new BPLC materials and new device structures have been investigated. In this paper, we demonstrate the stabilization a photopolymer-embedded blue phase liquid crystal precursor using a linearly polarized UV light for first time. When the UV polarization axis is perpendicular to the stripe electrodes of an IPS cell, anisotropic polymer networks are formed through the linear photo-polymerization process and the electrostriction effect is suppressed. As a result, the measured hysteresis is dramatically reduced from 6.95% to 0.36% and the response time shortened by ~2X compared to unpolarized UV exposure. To induce larger anisotropy in polymer networks for mitigating the electrostriction effect, high-intensity linearly polarized UV exposure is preferred. It is foreseeable this method will guide future BPLC device and material development as well as manufacturing process. The dawn of BPLCD is near.

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High‐Resolution Erasable “Live” Patterns Based on Controllable Ink Diffusion on the 3D Blue‐Phase Liquid Crystal Networks

Meng

Zheng

Yang

et al. 2022

Adv Funct Materials

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Colorful blue phase liquid crystal (BPLC) patterns have attracted wide research attention owing to their intriguing and advantageous properties and promising applications. However, it remains a challenge to develop novel and highresolution patterns from BPLC owing to the complicated synthetic procedure for the functional molecules. This study reports a high-resolution "live" pattern by well-designed diffusion of 5CB ink on the wettability-modified BPLC networks. Interestingly, the shape and color of the as-prepared pattern change with time, which results in unique spectra change of the printed pattern, "first red-shift and subsequent blue-shift of the stopband position" and "continuous growth in reflectivity intensity" with time. The hydrophobic substrate greatly suppresses the random spreading and diffusion of ink, contributing to highresolution patterns. The promising applications of live patterns for program display and active labels are demonstrated. Various high-resolution erasable colorful patterns are obtained. The structure reconfiguration of the writing and erasing processes is proved by transmitted electronic microscope images and Kossel diffraction diagrams, which ensures the reversible writing/erasing of the pattern on the membrane. This work is of significance for the development of novel rewritable paper and high-quality optic devices based on BPLC materials.

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Electro-optic response of polymer-stabilized blue phase liquid crystals

Cited by 61 publications

References 27 publications

Blue phase liquid crystal: strategies for phase stabilization and device development

Blue phase liquid crystal: strategies for phase stabilization and device development

Stabilizing blue phase liquid crystals with linearly polarized UV light

High‐Resolution Erasable “Live” Patterns Based on Controllable Ink Diffusion on the 3D Blue‐Phase Liquid Crystal Networks

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