Field induced and controlled heliconical structure of cholesteric liquid crystal

US9732277B2 · kind B2 · utility

Assignees

• Kent State University · US
• The University Court of the University of Aberdeen · GB

Inventors

• Oleg D. Lavrentovich · Kent, US
• Jie Xiang · San Jose, US
• Sergij V. Shiyanovskii · Stow, US
• Corrie T. Imrie · Aberdeen, GB
• Daniel A. Paterson · Aberdeen, GB
• John M. Storey · Aberdeen, GB

Key dates

• Filing date: Feb 25, 2016
• Grant date: Aug 15, 2017
• Expiry date: Feb 25, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K2019/0444
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A liquid crystal cell includes substrates defining a gap and electrodes having one of (i) an in-plane geometry generating an electric field parallel with the substrates and (ii) a top-down geometry generating an electric field across the gap between the two spaced apart substrates. A liquid crystal material disposed in the gap between the substrates comprises a chiral nematic material formed by a mixture of: 1-(4-cyanobiphenyl-4′-yl)-6-(4-cyanobiphenyl-4′-yloxy)hexane (CB6OCB) or α,ω-bis(4,4-cyanobiphenyl)nonane (CB9CB) dimeric liquid crystal material; at least one additional dimeric liquid crystal material; and a chiral dopant. The liquid crystal material within an operational range of electric field applied by the electrodes exhibits a heliconical state with an oblique angle helicoid director whose helicoid axis is oriented parallel with the electric field and whose helicoid pitch is sized to provide diffraction or Bragg reflection of light in a spectral range of interest impinging on one of the substrates of the liquid crystal cell.