Patents by Inventor Kristen P. Constant

Kristen P. Constant has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9400219
    Abstract: Metallic thermal emitters consisting of two layers of differently structured nickel gratings on a homogeneous nickel layer are fabricated by soft lithography and studied for polarized thermal radiation. A thermal emitter in combination with a sub-wavelength grating shows a high extinction ratio, with a maximum value close to 5, in a wide mid-infrared range from 3.2 to 7.8 ?m, as well as high emissivity up to 0.65 at a wavelength of 3.7 ?m. All measurements show good agreement with theoretical predictions. Numerical simulations reveal that a high electric field exists within the localized air space surrounded by the gratings and the intensified electric-field is only observed for the polarizations perpendicular to the top sub-wavelength grating. This result suggests how the emissivity of a metal can be selectively enhanced at a certain range of wavelengths for a given polarization.
    Type: Grant
    Filed: April 6, 2010
    Date of Patent: July 26, 2016
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Jae-Hwang Lee, Kai-Ming Ho, Kristen P. Constant
  • Patent number: 8742406
    Abstract: Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.
    Type: Grant
    Filed: February 16, 2012
    Date of Patent: June 3, 2014
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Wai Y. Leung, Joong-Mok Park, Zhengqing Gan, Kristen P. Constant, Joseph Shinar, Ruth Shinar, Kai-Ming Ho
  • Patent number: 8487283
    Abstract: A multi-channel polarized thermal emitter (PTE) is presented. The multi-channel PTE can emit polarized thermal radiation without using a polarizer at normal emergence. The multi-channel PTE consists of two layers of metallic gratings on a monolithic and homogeneous metallic plate. It can be fabricated by a low-cost soft lithography technique called two-polymer microtransfer molding. The spectral positions of the mid-infrared (MIR) radiation peaks can be tuned by changing the periodicity of the gratings and the spectral separation between peaks are tuned by changing the mutual angle between the orientations of the two gratings.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: July 16, 2013
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Jae-Hwang Lee, Kai-Ming Ho, Kristen P. Constant
  • Patent number: 8361545
    Abstract: A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: January 29, 2013
    Assignees: IUCF-HYU Industry-University Cooperation Foundation, Hanyang University, Iowa State University Research Foundation, Inc.
    Inventors: In Sung Park, Tae Ho Lee, Jin Ho Ahn, Rana Biswas, Kristen P. Constant, Kai-Ming Ho, Jae-Hwang Lee
  • Publication number: 20120031487
    Abstract: Nanoscale high-aspect-ratio metallic structures and methods are presented. Such structures may form transparent electrode to enhance the performance of solar cells and light-emitting diodes. These structures can be used as infrared control filters because they reflect high amounts of infrared radiation. A grating structure of polymeric bars affixed to a transparent substrate is used. The sides of the bars are coated with metal forming nanowires. Electrodes may be configured to couple to a subset of the rails forming interdigitated electrodes. Encapsulation is used to improve transparency and transparency at high angles. The structure may be inverted to facilitate fabrication of a solar cell or other device on the back-side of the structure. Multiple layered electrodes having an active layer sandwiched between two conductive layers may be used. Layered electro-active layers may be used to form a smart window where the structure is encapsulated between glass to modify the incoming light.
    Type: Application
    Filed: October 17, 2011
    Publication date: February 9, 2012
    Applicant: IOWA STATE UNIVERSITY RESEARCH FOUNDATION, INC.
    Inventors: Ping Kuang, Joong-Mok Park, Wai Leung, Kai-Ming Ho, Kristen P. Constant, Sumit Chaudhary
  • Publication number: 20110203656
    Abstract: Nanoscale high-aspect-ratio metallic structures and methods are presented. Such structures may form transparent electrode to enhance the performance of solar cells and light-emitting diodes. These structures can be used as infrared control filters because they reflect high amounts of infrared radiation. A grating structure of polymeric bars affixed to a transparent substrate is used. The sides of the bars are coated with metal forming nanowires. Electrodes may be configured to couple to a subset of the rails forming interdigitated electrodes. Encapsulation is used to improve transparency and transparency at high angles. The structure may be inverted to facilitate fabrication of a solar cell or other device on the back-side of the structure. Multiple layered electrodes having an active layer sandwiched between two conductive layers may be used. Layered electro-active layers may be used to form a smart window where the structure is encapsulated between glass to modify the incoming light.
    Type: Application
    Filed: February 14, 2011
    Publication date: August 25, 2011
    Applicant: IOWA STATE UNIVERSITY RESEARCH FOUNDATION, INC.
    Inventors: Ping Kuang, Joong-Mok Park, Wai Leung, Kai-Ming Ho, Kristen P. Constant, Sumit Chaudhary
  • Publication number: 20100294325
    Abstract: Metallic thermal emitters consisting of two layers of differently structured nickel gratings on a homogeneous nickel layer are fabricated by soft lithography and studied for polarized thermal radiation. A thermal emitter in combination with a sub-wavelength grating shows a high extinction ratio, with a maximum value close to 5, in a wide mid-infrared range from 3.2 to 7.8 ?m, as well as high emissivity up to 0.65 at a wavelength of 3.7 ?m. All measurements show good agreement with theoretical predictions. Numerical simulations reveal that a high electric field exists within the localized air space surrounded by the gratings and the intensified electric-field is only observed for the polarizations perpendicular to the top sub-wavelength grating. This result suggests how the emissivity of a metal can be selectively enhanced at a certain range of wavelengths for a given polarization.
    Type: Application
    Filed: April 6, 2010
    Publication date: November 25, 2010
    Applicant: IOWA STATE UNIVERSITY RESEARCH FOUNDATION, INC.
    Inventors: Jae-Hwang Lee, Kai-Ming Ho, Kristen P. Constant
  • Publication number: 20080231184
    Abstract: A metallic photonic crystal (MPC) structure used as a filter with incandescent lighting is presented that significantly improves efficiency, while retaining the desirable color rendering index of incandescent lighting. The resulting efficiency is higher than many existing lighting types. The MPC filter is implemented with only a single layer of square lattice or two layers of woodpile-like lattice has high reflection from the photonic band edge to infinitely long wavelength. The MPC filter can be used in a spherical, cylindrical or flat form depending on the illumination scheme.
    Type: Application
    Filed: February 15, 2008
    Publication date: September 25, 2008
    Applicant: Iowa State University Research Foundation, Inc.
    Inventors: Jae-Hwang Lee, Yong-Sung Kim, Joong-Mok Park, Kai-Ming Ho, Kristen P. Constant