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Proceedings Paper

Slippery interfaces: lubrication of director and helix rotation motions (Conference Presentation)
Author(s): Jun Yamamoto; Waki Sakatsuji; Isa Nishiyama

Paper Abstract

Anchoring effects on the polymer films in the liquid crystal (LC) display devices plays key role to create the restoring force to the black state. However, the chiral materials with spontaneous helix, such as deformed helix mode in SmC* (DH-FLC) or the polymer stabilized blue phase (PSChBP), can recover black state by rewinding motion of the helix itself. We have invented the principle and design of slippery interfaces, which has zero anchoring force for attached LC molecules on the interfaces, and confirmed the drastic reduction of driving voltage in DH-FLC mode of SmC* (<1 order) keeping the fast switching response (tau~50 micro sec). We have reported the lateral slippery interfaces consist of the phase separated liquid phases created by tran-cis isomerization of doped azo dye. It is not enough to the complete transmission of the light(I/I0~1) by applying the typical driving voltage (~1.0V/micro m) for current IPS panels. It is also problem that slippery interface become effective only just below the I-SmC phase transition temperature (TIC-T<20°). Here, we report new type of the vertical slippery interface realized by the spin coated swollen azo-LC gel films on the glass substrates. Under UV irradiation, trans-cis isomerization of the azo-dye co-polymerized in the azo-LC gel film, induces the vertical slippery interfaces by the disordering effect. Since the co-polymerized azo-dye cannot be dissolved into LC, the disordering effect is completely localized in the interface between swollen azo-LC gel and bulk SmC* material. Then the slippery interfaces can be stabilized over wide temperature range. We greatly improve the reduction of the driving voltage, I/Io=1, 1.0V/micro m for rather slow change of the driving voltage (tau~1msec 2.5msec pulse), I/I0=0.6, 1.5V/micro m for fast change (tau~50 micro sec, 250 micro sec pulse) by lubrication of intra and inter helix C-director rotation motions.

Paper Details

Date Published: 21 April 2017
PDF: 1 pages
Proc. SPIE 10125, Emerging Liquid Crystal Technologies XII, 101250D (21 April 2017); doi: 10.1117/12.2251313
Show Author Affiliations
Jun Yamamoto, Kyoto Univ. (Japan)
Japan Science and Technology Agency (Japan)
Waki Sakatsuji, Kyoto Univ. (Japan)
Japan Science and Technology Agency (Japan)
Isa Nishiyama, Dainippon Ink and Chemicals, Inc. (Japan)
Japan Science and Technology Agency (Japan)

Published in SPIE Proceedings Vol. 10125:
Emerging Liquid Crystal Technologies XII
Liang-Chy Chien, Editor(s)

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