Large range electrically-induced reflection notch tuning in polymer stabilized cholesteric liquid crystals

2015 ◽  
Vol 3 (34) ◽  
pp. 8788-8793 ◽  
Author(s):  
Kyung Min Lee ◽  
Vincent P. Tondiglia ◽  
Taewoo Lee ◽  
Ivan I. Smalyukh ◽  
Timothy J. White
Keyword(s):  
Liquid Crystals ◽  
Direct Current ◽  
Large Range ◽  
Dielectric Anisotropy ◽  
Cholesteric Liquid Crystals ◽  
Large Magnitude ◽  
Polymer Stabilized

This communication reports large magnitude (exceeding 1500 nm) and reversible reflection notch tuning in polymer stabilized cholesteric liquid crystals (PSCLCs) formulated with negative dielectric anisotropy (−Δε) hosts upon application of a direct current (DC) field.

Blue-shifting tuning of the selective reflection of polymer stabilized cholesteric liquid crystals

Soft Matter ◽  
2017 ◽  
Vol 13 (35) ◽  
pp. 5842-5848 ◽  
Author(s):  
Kyung Min Lee ◽  
Vincent P. Tondiglia ◽  
Nicholas P. Godman ◽  
Claire M. Middleton ◽  
Timothy J. White
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Dielectric Anisotropy ◽  
Cholesteric Liquid Crystals ◽  
Large Magnitude ◽  
Selective Reflection ◽  
Polymer Stabilized

We report on electrically-induced, large magnitude (>300 nm), and reversible tuning of the selective reflection in polymer stabilized cholesteric liquid crystals (PSCLCs) prepared from negative dielectric anisotropy nematic liquid crystal hosts.

Enhanced reflection band broadening in polymer stabilized cholesteric liquid crystals with negative dielectric anisotropy

2018 ◽  
Vol 267 ◽  
pp. 120-126 ◽  
Author(s):  
Hossein Nemati ◽  
Shiyi Liu ◽  
Alireza Moheghi ◽  
Vincent P. Tondiglia ◽  
Kyung Min Lee ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Dielectric Anisotropy ◽  
Band Broadening ◽  
Cholesteric Liquid Crystals ◽  
Reflection Band ◽  
Polymer Stabilized

scholarly journals Effect of Cell Thickness on the Electro-optic Response of Polymer Stabilized Cholesteric Liquid Crystals with Negative Dielectric Anisotropy

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 746 ◽  
Author(s):  
Kyung Min Lee ◽  
Ecklin P. Crenshaw ◽  
Mariacristina Rumi ◽  
Timothy J. White ◽  
Timothy J. Bunning ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Field Strength ◽  
Polymer Network ◽  
Dielectric Anisotropy ◽  
Cholesteric Liquid Crystals ◽  
Colored State ◽  
Electro Optic ◽  
Dc Electric Field ◽  
Polymer Stabilized ◽  
Cell Thickness

It has previously been shown that for polymer-stabilized cholesteric liquid crystals (PSCLCs) with negative dielectric anisotropy, the position and bandwidth of the selective reflection notch can be controlled by a direct-current (DC) electric field. The field-induced deformation of the polymer network that stabilizes the devices is mediated by ionic charges trapped in or near the polymer. A unique and reversible electro-optic response is reported here for relatively thin films (≤5 μm). Increasing the DC field strength redshifts the reflection notch to longer wavelength until the reflection disappears at high DC fields. The extent of the tuning range is dependent on the cell thickness. The transition from the reflective to the clear state is due to the electrically controlled, chirped pitch across the small cell gap and not to the field-induced reorientation of the liquid crystal molecules themselves. The transition is reversible. By adjusting the DC field strength, various reflection wavelengths can be addressed from either a different reflective (colored) state at 0 V or a transparent state at a high DC field. Relatively fast responses (~50 ms rise times and ~200 ms fall times) are observed for these thin PSCLCs.

Voltage-Induced Cholesteric Structure-Transformation in Thin Layers

1981 ◽  
Vol 36 (7) ◽  
pp. 718-726 ◽  
Author(s):  
Paul R. Gerber
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Thin Layers ◽  
Dielectric Anisotropy ◽  
Structure Transformation ◽  
Cholesteric Liquid Crystals ◽  
Threshold Voltages

Abstract o lta g e -In d u c e d C h o le s te r ic S tr u c tu r e -T r a n s f o r m a tio n in T h i n L a y e rs Measurements of various threshold voltages which occur in thin layers of cholesteric liquid crystals with positive dielectric anisotropy under homeotropic wall-alignment conditions are presented. Characteristic times are determined for some of the structure-changing processes which take place under application of electric-field changes. The measurements have been performed for various pitch-to-thickness ratios, and are expressed in empirical formulae.

scholarly journals Deformation-free switching of polymer-stabilized cholesteric liquid crystals by low-temperature polymerization

2016 ◽  
Vol 6 (3) ◽  
pp. 705 ◽  
Author(s):  
Hoekyung Kim ◽  
Yo Inoue ◽  
Junji Kobashi ◽  
Yasutaka Maeda ◽  
Hiroyuki Yoshida ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Low Temperature ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized

Broadband Reflection in Polymer‐Stabilized Cholesteric Liquid Crystals via Thiol–Acrylate Chemistry

2019 ◽  
Vol 58 (20) ◽  
pp. 6698-6702 ◽  
Author(s):  
Wei Hu ◽  
Mei Chen ◽  
Qian Wang ◽  
Lanying Zhang ◽  
Xiaotao Yuan ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized

Photosensitivity of reflection notch tuning and broadening in polymer stabilized cholesteric liquid crystals

Soft Matter ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1256-1261 ◽  
Author(s):  
Kyung Min Lee ◽  
Vincent P. Tondiglia ◽  
Timothy J. White
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized

Optical Properties of Polymer Stabilized Cholesteric Liquid Crystals

2002 ◽  
Vol 277 (1) ◽  
pp. 75-83 ◽  
Author(s):  
V. Laux ◽  
F. Roussel ◽  
J.-M. Buisine
Keyword(s):  
Optical Properties ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Polymer Stabilized
Sign in / Sign up

Export Citation Format

Share Document