Kent State University

The University Court of the University of Aberdeen

Sergij V Shiyanovskii

Oleg D Lavrentovich

Dmitry Voloschenko

Mingxia Gu

Andrii B Golovin

Qi-Huo Wei

Yubing Guo

Chenhui Peng

Jie V Xiang

John M Storey

Volodymyr Borshch

Corrie T Imrie

Ye Yin

Yuriy A Nastyshyn

Vassili G Nazarenko

Roman M Vasyuta

Daniel A Paterson

Oleksandr P Boiko

A transport device comprises: a fluid cell comprising parallel substrates; an anisotropic electrolyte disposed in the fluid cell; and electrodes configured to apply an AC electric field to the anisotropic electrolyte disposed in the fluid cell. A substrate of the fluid cell includes a pattern that induces a director distortion pattern in the anisotropic electrolyte disposed in the fluid cell. The director distortion pattern has a gradient configured to induce electrokinetic flow of the anisotropic electrolyte in the fluid cell in response to the AC electric field applied by the electrodes. Cargo, such as particles, gas bubbles, or fluid, is dispersed in the anisotropic electrolyte and transported in the fluid cell by the induced electrokinetic flow of the anisotropic electrolyte. The induced electrokinetic flow may be linear, curvilinear, circular so as to induce mixing, depending on the predesigned director pattern. The director pattern might be nonsingular (defect free) or may contain defects such as disclinations that produce pumping effects and can trap cargo at a core of the disclination.

Liquid crystals with patterned molecular orientation as an electrolytic active medium

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&#x2032;-yloxy)hexane (CB6OCB) or &#x3b1;,&#x3c9;-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.

Field induced and controlled heliconical structure of cholesteric liquid crystal

An optical modulator includes a liquid crystal cell containing liquid crystal material having liquid crystal molecules oriented along a quiescent director direction in the unbiased state, and a voltage source configured to apply an electric field to the liquid crystal material wherein the direction of the applied electric field does not cause the quiescent director direction to change. An optical source is arranged to transmit light through or reflect light off the liquid crystal cell with the light passing through the liquid crystal material at an angle effective to undergo phase retardation in response to the voltage source applying the electric field. The liquid crystal material may have negative dielectric anisotropy, and the voltage source configured to apply an electric field to the liquid crystal material whose electric field vector is transverse to the quiescent director direction. Alternatively, the liquid crystal material may have positive dielectric anisotropy and the voltage source configured to apply an electric field to the liquid crystal material whose electric field vector is parallel with the quiescent director direction.

Nanosecond liquid crystalline optical modulator

The invention provides a liquid crystal cell and method thereof. The cell comprises two opposed substrates and a surfactant-free lyotropic chromonic liquid crystals (LCLC) material disposed therebetween. By using an ammonium compound with LCLC or surface treatment on the substrates, the alignment of the LCLC material can be manipulated as a homeotropic bulk alignment; or a hybrid bulk alignment in which the LCLC alignment is changed from homeotropic bulk alignment in the vicinity of one substrate to planar alignment in the vicinity of another substrate. The cell can be used in biosensing, detection and amplification of ligands, optical devices, and photovoltaics etc.

Homeotropic and hybrid bulk alignment of lyotropic chromonic liquid crystals

The invention provides a liquid crystal device and method thereof. Subsequent to applying a first electrical voltage on a liquid crystal to induce a reorientation of the liquid crystal, a second electrical voltage with proper polarity is applied on the liquid crystal to assist the relaxation of the reorientation that was induced by the first electrical voltage. The 'switch-off' phase of the liquid crystal can therefore be accelerated or temporally shortened, and the device can exhibit better performance such as fast response to on/off signals. The invention can be widely used LCD, LC shutter, LC lens, spatial light modulator, telecommunication device, tunable filter, beam steering device, and electrically driven LC device, among others.

Liquid crystal device and method thereof

A method for fast switching a dual frequency (FIG.) liquid crystal cell is disclosed. The liquid crystal cell has opposed substrates () with a dual frequency liquid crystal material () disposed therebetween. Each substrate has an electrode that is connected to a power supply () that is able to apply different voltage magnitudes at different frequencies. And each substrate () has an alignment layer that imparts a high pretilt angle to the liquid crystal material, wherein no application of voltage results in the material exhibiting an initial state. A transition driving pulse () of a first magnitude is applied to the material at a first frequency to accelerate a transition into a first state from the initial state. A holding pulse () of a second magnitude is applied to the material at the first frequency to maintain the first state, wherein the second magnitude is less than the first magnitude.

Fast switching dual-frequency liquid crystal cells and method for driving the same

A liquid crystal device comprises a first and second cell wall structure; at least one liquid crystal material disposed within a space between the first and second cell wall structures; and polymer micro-structures, wherein the micro-structures are formed by polymerizing a prepolymer, and wherein said micro-structures have a shape and spatial location determined by said liquid crystal material. Permanent polymer micro-structures are formed from a liquid crystal with a non-uniform spatially modulated director field. The polymer structures have the shape and spatial location dictated by the non-uniform director field of the liquid crystal. The micro-structures are a backbone that restores the liquid crystal director field that existed during the polymerization process even when other factors, such as electric field, temperature, or surface anchoring, do not favor this restoration. The polymer micro-structures can be used in optical devices, such as diffraction gratings and deflecting and beam steering devices, and in micro-mechanical and micro-fluidic devices.

Growing community of inventors

Stow, OH, United States of America

Sergij V Shiyanovskii