Plasma beam alignment for the large‐area substrates: Equipment and process

Yaroshchuk, O.; Kravchuk, R.; Dobrovolskyy, Andriy; Liu, P. C.; Lee, C. D.

doi:10.1889/1.1904928

Cited by 17 publications

(22 citation statements)

References 18 publications

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“…Thus, there is an urgent need for such an alignment process, which can combine the advantages of rubbed and non-rubbed aligning layers. In present study this is achieved by using plasma beam (PB) alignment technique earlier adopted for nematic [2,3] and ferroelectric [4] thermotropic LCs, reactive mesogens [5], and lyotropic chromonic LCs [6]. Good potential of this technique for alignment patterning and formation of uniform and stable ULH textures of CLC is also demonstrated.…”

Section: Introductionmentioning

confidence: 91%

“…Plasma Setup for Alignment Processing: The films were obliquely treated by the beam of Ar plasma from anode layer source using in-house made processing tool described in our previous papers [2,3]. The processing scheme is presented in Fig.…”

Section: Experimental Partmentioning

confidence: 99%

“…Based on the fact that PB processing causes anchoring transition from H to P alignment [3], patterning of the aligning layers of H-PI was realized. For this purpose, H-type polyimide films were exposed through the mask, which was a sheet of perforated paper.…”

Section: Alignment Patterningmentioning

confidence: 99%

See 2 more Smart Citations

P.99: Alignment Peculiarities of Cholesteric Liquid Crystals on the Surfaces Processed by Plasma Beam

Kravchuk

Yaroshchuk

2013

Symp Digest of Tech Papers

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It is demonstrated that plasma beam alignment process allows one to combine uniformity of planar texture and stability of focal conic texture of cholesteric liquid crystals (CLC) and thus obtain highly contrast and truly bistable samples. It provides suitable anchoring conditions for ULH texture. It can also be readily applied for the alignment patterning that opens new prospects for CLC devices. Author Keywordsliquid crystal alignment; ion beam alignment; plasma beam alignment; cholesteric liquid crystal; reflective display, ULH texture.

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Section: Introductionmentioning

confidence: 91%

Section: Experimental Partmentioning

confidence: 99%

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P.99: Alignment Peculiarities of Cholesteric Liquid Crystals on the Surfaces Processed by Plasma Beam

Kravchuk

Yaroshchuk

2013

Symp Digest of Tech Papers

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“…This situation stimulates development of alternative alignment methods. Recent years were marked by the great interest to so called ion= plasma beam alignment, which has shown high efficiency for LCs [1][2][3][4][5][6][7][8] and reactive mesogens [9]. The essence of the method is that surfaces treated by ion or plasma beams from oblique angle develop an ability to align LCs.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the unique feature of this technique is that presence of alignment layer is optional; i.e., LC can be aligned directly on bare substrates, e.g., glass, silicon, plastic, etc. [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Plasma Beam Alignment of Liquid Crystals on the Bare Glass: Modification of Surface Chemical Composition

Kravchuk

Artyushkova

Yaroshchuk

2011

Molecular Crystals and Liquid Crystals

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X-ray Photoelectron Spectroscopy was applied to study the chemical composition of the modified glass surfaces by the flux of accelerated Ar or Ar=H 2 plasma in order to clarify mechanisms of liquid crystal (LC) alignment on these surfaces. It was established that the surface of prinstine glass exposed to air contains carbonaceous contamination layer consisting of about 50% of aliphatic=aromatic carbon and about 50% of C-O moieties of various types. Plasma processing results in partial ablation of this layer and modification of its chemical composition. This suggests that LCs are actually being aligned by the plasma modified carbonaceous layer rather than by a pure glass.

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Surface reformed anisotropic polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride layer via ion‐beam irradiation for liquid crystals

Kim

Lee

et al. 2022

Polymers for Advanced Techs

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The surface modifications and liquid crystal (LC) alignment properties of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (SEBS-g-MA) films induced by ion-beam (IB) irradiation are reported herein.Changes to the surfaces of the SEBS-g-MA films from IB irradiation at various incidence angles and changes in the LC orientations upon LC cell fabrication were analyzed. The physical surface modifications due to IB irradiation were observed via atomic force microscopy. Additionally, changes in the molecular composition of the surface were observed through X-ray photoelectron spectroscopy analysis. Polarized optical microscopy analysis shows that excellent LC alignment properties could be obtained after IB irradiation at angles exceeding 45 . Further, the anisotropy caused by IB irradiation was more responsible for uniform LC alignment than the corrugated pattern.atomic force microscopy, ion-beam irradiation, liquid crystal alignment, polystyrene-block-poly (ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride, X-ray photoelectron spectroscopy | INTRODUCTIONIn liquid crystal (LC) displays, the alignment technology that controls the directions of the LC molecules is an important factor. 1 Among the available LC alignment technologies, the rubbing method is the most common, 2-5 wherein the alignment film is physically rubbed to create grooves in specific directions such that the LCs are aligned along these grooves. However, owing to the nature of the rubbing process, static electricity or scratches can occur, which may affect the uniformity of the grooves and hence the LC arrangement. To overcome these shortcomings, other nonrubbing methods, such as photoalignment, 6-8 plasma-beam alignment, 9 atmospheric pressure, 10 ion-beam (IB) irradiation, 11,12 and nanoimprinting lithography, [13][14][15] have been studied. Of these, the IB irradiation method is used in the present study and involves applying an Ar + ion-induced plasma beam onto a film to supply energy to its surface, thereby inducing uniform alignment. This method has the advantage of producing strong LC alignment effects in both organic and inorganic materials.Many polymers, such as polyimide, polystyrene, and poly(ethylene glycol), have been used to fabricate the LC alignment layers. Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (SEBS-g-MA) is a functional triblock copolymer with high impact strength, rigidity, and transmittance, which makes it an excellent option for display materials. [16][17][18][19] In addition, owing to the maleic anhydride group, SEBS-g-MA can be used as a compatibilizer. Recently, studies on the possibility of IB-irradiated SEBS-g-MA film as an LC alignment layer have been conducted. 20 In this paper, we analyzed the surface modification and anisotropy of SEBS-g-MA film according to the IB irradiation angle, and studied the LC alignment characteristics accordingly. Depending on the IB

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Plasma beam alignment for the large‐area substrates: Equipment and process

Cited by 17 publications

References 18 publications

P.99: Alignment Peculiarities of Cholesteric Liquid Crystals on the Surfaces Processed by Plasma Beam

P.99: Alignment Peculiarities of Cholesteric Liquid Crystals on the Surfaces Processed by Plasma Beam

Plasma Beam Alignment of Liquid Crystals on the Bare Glass: Modification of Surface Chemical Composition

Surface reformed anisotropic polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride layer via ion‐beam irradiation for liquid crystals

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