Patents Assigned to Kent State University
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Patent number: 9323113Abstract: Electro-optic lenses, including liquid crystals, wherein the power of the lenses can be modified by application of an electric field. In one embodiment, the liquid crystal-based lenses include ring electrodes having a resistive bridge located between adjacent electrodes, and in a preferred embodiment, input connections for several electrode rings are spaced on the lens. In a further embodiment, liquid crystal-based lenses are provided that can increase optical power through the use of phase resets, wherein in one embodiment, a lens includes ring electrodes on surfaces of the substrates on opposite sides of the liquid crystal cell such that a fixed phase term can be added to each set of electrodes that allows for phase change across each group of electrodes to be the same and also be matched with respect to a previous group.Type: GrantFiled: May 23, 2013Date of Patent: April 26, 2016Assignee: KENT STATE UNIVERSITYInventors: Philip Bos, Douglas Bryant, Lei Shi, Bentley Wall
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Patent number: 9314931Abstract: A robotic fuel cell assembly system includes an end-effector, robotic workcell, and fuel cell components that have integrated design features that allow accurate component alignment during the assembly process of a fuel cell stack within a desired tolerance, while avoiding component overlap, which is a major cause of overboard gas leaks during the fuel cell operation. Accurate component alignment is achieved by electrically non-conductive alignment pins that are mounted on a fuel cell base plate, which are configured to be received by guide holes formed on the fuel cell components, and alignment holes provided by an alignment arm attached to the end-effector. The end-effector also includes a passive compliance system that includes two perpendicularly mounted miniature linear blocks and rails, which serve to compensate for the limitations in the ability of the robotic arm to move the end-effector accurately in a repeated manner.Type: GrantFiled: December 11, 2014Date of Patent: April 19, 2016Assignee: Kent State UniversityInventor: Vladimir Gurau
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Patent number: 9304350Abstract: An encapsulated polymer stabilized cholesteric texture (EPSCT) light shutter is formed from a cholesteric liquid crystal and monomer that is encapsulated into micron sized, polymer-coated droplets by either an emulsification or phase separation process. The polymer-coated droplets are disposed between transparent electrodes, where they are irradiated by ultra-violet (UV) light to polymerize the monomer.Type: GrantFiled: June 3, 2013Date of Patent: April 5, 2016Assignee: Kent State UniversityInventors: Deng-Ke Yang, Yue Cui, Cuiyu Zhang
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Publication number: 20160085095Abstract: A polymer-dispersed blue-phase (PDBP) liquid crystal film is formed from a polymer-based latex and blue-phase liquid crystals that are combined using an emulsification process or a polymerization-induced phase separation process. The resultant PDBP liquid crystal film includes droplets formed by the polymer-based latex that encapsulate the blue-phase liquid crystals therein, so as to allow the blue-phase liquid crystals to have a blue phase at room temperature. As such, the PDBP liquid crystal film is conducive for use in manufacturing processes, such as LCD (liquid crystal display) manufacturing processes, while providing desirable optical features, such as field-induced birefringence at low switching voltages.Type: ApplicationFiled: November 24, 2015Publication date: March 24, 2016Applicant: Kent State UniversityInventors: Liang-Chy Chien, Jeoung-Yeon Hwang, Emine Kemiklioglu
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Patent number: 9280020Abstract: Electro-optic lenses, including liquid crystals, wherein the power of the lenses can be modified by application of an electric field. In one embodiment, the liquid crystal-based lenses include ring electrodes having a resistive bridge located between adjacent electrodes, and in a preferred embodiment, input connections for several electrode rings are spaced on the lens. In a further embodiment, liquid crystal-based lenses are provided that can increase optical power through the use of phase resets, wherein in one embodiment, a lens includes ring electrodes on surfaces of the substrates on opposite sides of the liquid crystal cell such that a fixed phase term can be added to each set of electrodes that allows for phase change across each group of electrodes to be the same and also be matched with respect to a previous group.Type: GrantFiled: June 17, 2010Date of Patent: March 8, 2016Assignee: KENT STATE UNIVERSITYInventors: Philip Bos, Douglas Bryant, Lei Shi, Bentley Wall
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Patent number: 9261745Abstract: A phase retarder comprises first and second ?-cells or other tunable birefringent devices arranged optically in series. The phase retardation value of the phase retarder is a difference between the phase retardation values of the first and second ?-cells. Driving circuitry drives the phase retarder to generate a target phase retardation value by: (1) prior to a relaxation period, biasing the ?-cells to produce the target phase retardation value; (2) during the relaxation period, biasing the first ?-cell at a constant bias value; and (3) during the relaxation period, lowering the bias value of the second ?-cell continuously or stepwise to maintain the target phase retardation value for the phase retarder throughout the relaxation period. In some embodiments the operation (2) comprises applying zero bias to the first ?-cell throughout the relaxation period. In some embodiments the operation (1) comprises applying a maximum operational bias to the second ?-cell.Type: GrantFiled: May 13, 2013Date of Patent: February 16, 2016Assignee: Kent State UniversityInventors: Hsienhui Cheng, Achintya Bhowmik, Philip J. Bos
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Publication number: 20160018681Abstract: A bistable liquid crystal spatial light modulating (SLM) device (SLM) device utilizes the homeotropic and bubble domain texture change of a cholesteric liquid crystal that is responsive to external stimuli, such as electric voltage, light and pressure. The SLM device is configured to be switched between the two stable textures of the bubble domain texture or the fingerprint texture. In addition, the SLM device may be switched between transparent and light-scattering states by the application of an electric field, light irradiation or physical/mechanical pressure. The light transmission state and the light-scattering states of the present invention are also stable in time at zero voltage, and are reversible upon the application of an external field at a different voltage, frequency or wavelength of light.Type: ApplicationFiled: July 21, 2015Publication date: January 21, 2016Applicant: KENT STATE UNIVERSITYInventors: Liang-Chy Chien, Andrii Varanytsia
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Publication number: 20160018679Abstract: 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.Type: ApplicationFiled: July 16, 2014Publication date: January 21, 2016Applicant: KENT STATE UNIVERSITYInventors: Sergij V. Shiyanovskii, Volodymyr Borshch, Oleg D. Lavrentovich
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Patent number: 9233481Abstract: A method of patterning an electrically-conductive film is performed by providing a flexible substrate that carries the electrically-conductive film thereon to form a combined layer. The combined layer is then bent about a radius of curvature, so as to impart a stress on the brittle conductive film along the axis of curvature of the curved surface. The application of the stress to the conductive film results in the formation of crack lines that are substantially perpendicular to the direction to which the substrate and conductive film are bent. The crack lines serve to define and electrically isolate conductive sections therebetween that can be utilized as electrodes and address lines in electronic devices.Type: GrantFiled: December 20, 2012Date of Patent: January 12, 2016Assignee: Kent State UniversityInventors: John L. West, Da-Wei Lee
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Patent number: 9198988Abstract: This invention discloses a synthetic procedure for preparing nanoparticulate materials of various metal cyanide compounds containing manganese(II) ions in the crystal lattice with the surfaces coated by a hydrophilic compound, and their use as MRI contrast agents with high sensitivity, long blood circulation half lives and low toxicity at low-field and high field MR scanners.Type: GrantFiled: August 29, 2011Date of Patent: December 1, 2015Assignee: Kent State UniversityInventors: Songping D. Huang, Anatoly K. Khitrin, Vindya S. Perera, Murthi S. Kandanapitiye
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Patent number: 9182618Abstract: A method of electrophoretic movement of liquid droplets/gas bubbles through a liquid crystal utilizes a direct (DC) or alternating (AC) electric field that is applied along the liquid crystal director (for liquid crystals with a positive dielectric anisotropy) or perpendicular to the director (for liquid crystals with a negative dielectric anisotropy). A perpendicular or tilted orientation of the liquid crystal molecules at the surface of the liquid droplet/gas bubble causes distortions, such that the fore-aft (or left-right) symmetry of the liquid droplet/gas bubble is broken. The asymmetric orientation of the liquid crystal around the liquid droplet/gas bubble allows both charged and neutral particles to be transported, even when the liquid droplets/gas bubbles themselves are perfectly symmetric (spherical).Type: GrantFiled: June 1, 2015Date of Patent: November 10, 2015Assignee: Kent State UniversityInventors: Oleg D. Lavrentovich, Israel Esteban Lazo-Martinez, Oleg P. Pishnyak
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Publication number: 20150233816Abstract: Systems and methods for detection of an amphiphile at a liquid crystal interface include the production of circular polarized light. A system 100 for detecting an amphiphile at a liquid crystal interface comprises a source of white collimated light. A circular polarizer is included for circularly polarizing incoming white light. Polarized white light passes through to an LC grid including a suspended LC film and a solution in contact with the LC grid at a surface. A spectrophotometer optically detects the presence of an amphiphile at the surface by determining a change in birefringence exhibited by the suspended LC film. A method for detecting amphiphiles at a liquid crystal water interface comprises shining collimated white light on an LC cell including an LC film, polarizing the white light with a circular polarizer, adding an amphiphile to a solution in contact with the LC film, and optically detecting the presence of the amphiphile by measuring a change in birefringence exhibited by the LC film.Type: ApplicationFiled: February 13, 2015Publication date: August 20, 2015Applicant: Kent State UniversityInventors: Antal JAKLI, Elizabeth MANN, Piotr POPOV
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Patent number: 9086596Abstract: A surface-stabilized in-plane switching (SS-IPS) liquid crystal (LCD) cell includes a pair of spaced substrates that include alignment layers disposed thereon. The alignment layers are treated to define a first director orientation. Disposed between the alignment layers is a liquid crystal material that contains polymer fibrils that are disposed upon each of the alignment layers. The polymer fibrils serve to maintain the alignment of the liquid crystal molecules in the first director orientation when no voltage is applied to the LCD cell via interdigitated electrodes disposed upon the alignment layers, thus improving the dynamic response of the SS-IPS LCD cell.Type: GrantFiled: June 27, 2013Date of Patent: July 21, 2015Assignee: Kent State UniversityInventors: Liang-Chy Chien, Jeoung-Yeon Hwang
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Patent number: 9085730Abstract: The invention provides a liquid crystal (LC) composition, a LC cell thereof, and a LC device thereof. The LC composition comprises (i) a mixture of two or more nematic liquid crystals, and (ii) at least one chiral dopant. The mixture of the liquid crystals can exist in a blue phase within a temperature range of from about 12-60° C. such as 21-28° C. The LC device can be a blue phase mode liquid crystal display (BPLCD) based on such a room-temperature blue phase LC. The BPLCD requires no alignment, and it exhibits merits such as a fast switching time (e.g. sub-millisecond), a low switching voltage and a large field-induced birefringence, among others.Type: GrantFiled: June 16, 2010Date of Patent: July 21, 2015Assignee: Kent State UniversityInventors: Liang-Chy Chien, Lu Lu, Jeoung Yeon Hwang
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Publication number: 20150173679Abstract: A thermochromic fabric utilizing cholesteric liquid crystals includes a fabric material or garment formed therefrom. The liquid crystal material is patterned with a plurality of different liquid crystal formulations, whereby each formulation has high thermal sensitivity over a narrow temperature range. As a result, the aggregate pattern of liquid crystal material formed on the thermochromic fabric allows the thermochromic fabric to have high thermal sensitivity over a broad temperature range. As such, the fabric or garment may be worn on specific body parts of a patient, such as his or her feet, to assist in making a medical diagnosis.Type: ApplicationFiled: December 19, 2014Publication date: June 25, 2015Applicant: KENT STATE UNIVERSITYInventors: John L. West, Yijing Chen, Peter Palffy-Muhoray, Lawrence Osher, Vincent J. Hetherington, Jill S. Kawalec
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Patent number: 9063358Abstract: A multi-functional photochromic chiral nematic liquid crystal window comprises at least a photochromic chiral nematic liquid crystal layer. The windows are able to not only to darken in color upon exposure to sunlight irradiation but also control the light and the heat passing through them, which can be used as the windows of buildings, vehicles, and the like.Type: GrantFiled: February 25, 2011Date of Patent: June 23, 2015Assignee: KENT STATE UNIVERSITYInventors: Quan Li, Yannian Li, Ji Ma
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Publication number: 20150158179Abstract: A robotic fuel cell assembly system includes an end-effector, robotic workcell, and fuel cell components that have integrated design features that allow accurate component alignment during the assembly process of a fuel cell stack within a desired tolerance, while avoiding component overlap, which is a major cause of overboard gas leaks during the fuel cell operation. Accurate component alignment is achieved by electrically non-conductive alignment pins that are mounted on a fuel cell base plate, which are configured to be received by guide holes formed on the fuel cell components, and alignment holes provided by an alignment arm attached to the end-effector. The end-effector also includes a passive compliance system that includes two perpendicularly mounted miniature linear blocks and rails, which serve to compensate for the limitations in the ability of the robotic arm to move the end-effector accurately in a repeated manner.Type: ApplicationFiled: December 11, 2014Publication date: June 11, 2015Applicant: KENT STATE UNIVERSITYInventor: Vladimir Gurau
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Patent number: 9052562Abstract: A method of electrophoretic movement of particles through a liquid crystal utilizes a direct (DC) or alternating (AC) electric field that is applied along the liquid crystal director (for liquid crystals with a positive dielectric anisotropy) or perpendicular to the director (for liquid crystals with a negative dielectric anisotropy). A perpendicular or tilted orientation of the liquid crystal molecules at the surface of the particle causes distortions, such that the fore-aft (or left-right) symmetry of the particle is broken. The asymmetric orientation of the liquid crystal around the particle allows both charged and neutral particles to be transported, even when the particles themselves are perfectly symmetric (spherical).Type: GrantFiled: December 13, 2011Date of Patent: June 9, 2015Assignee: Kent State UniversityInventors: Oleg D. Lavrentovich, Israel Esteban Lazo-Martinez, Oleg P. Pishnyak
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Patent number: 9040229Abstract: A method of tilting liquid crystal molecules is presented. The method entails providing a substrate including a photoalignment layer on top of a layer of liquid crystal molecules. The photoalignment layer is exposed to patterned light that is incident on the substrate at a substantially normal angle. The patterned light is polarized in a polarization direction that is non-parallel to an incident surface of the substrate.Type: GrantFiled: January 25, 2013Date of Patent: May 26, 2015Assignee: KENT STATE UNIVERSITYInventor: Hiroshi Yokoyama
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Publication number: 20150112986Abstract: Embodiments disclosed herein provide systems and methods for scaling reachability computations on relatively large graphs. In an embodiment, a method provides for scaling reachability computations on relatively large graphs, the method comprising, identifying an initial graph comprising a plurality of vertices and a plurality of edges, processing at least a portion of the plurality of vertices and at least a portion of the plurality of edges to generate a plurality of reachability indices for the at least a portion of the plurality of vertices, and generating a backbone graph comprising a scaled-down version of the initial graph, based at least in part on at least one of the plurality of reachability indices.Type: ApplicationFiled: October 21, 2014Publication date: April 23, 2015Applicant: KENT STATE UNIVERSITYInventor: RUOMING JIN