Patents by Inventor Helen M. Chan

Helen M. Chan 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: 8541252
    Abstract: The use of an abbreviated GaN growth mode on nano-patterned AGOG sapphire substrates, which utilizes a process of using 15 nm low temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated at least a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: September 24, 2013
    Assignee: Lehigh University
    Inventors: Nelson Tansu, Helen M. Chan, Richard P. Vinci, Yik-Khoon Ee, Jeffrey Biser
  • Publication number: 20110147703
    Abstract: The use of an abbreviated GaN growth mode on nano-patterned AGOG sapphire substrates, which utilizes a process of using 15 nm low temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated at least a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.
    Type: Application
    Filed: December 17, 2010
    Publication date: June 23, 2011
    Applicant: LEHIGH UNIVERSITY
    Inventors: Nelson Tansu, Helen M. Chan, Richard P. Vinci, Yik-Khoon Ee, Jeffrey Biser
  • Publication number: 20100144511
    Abstract: Inorganic microporous metal oxide materials, such as aluminum-based microporous ceramic materials, useful for loop heat pipes, insulators, thermal management devices, catalyst supports, substrates, and filters, among others. An example method of manufacture includes heating a mixture of alumina (Al2O3) and aluminum carbonate (Al2(CO3)3) powders to a temperature of at least about 1400 degrees Celsius for a pre-selected time.
    Type: Application
    Filed: July 21, 2009
    Publication date: June 10, 2010
    Applicant: LEHIGH UNIVERSITY
    Inventors: Helen M. Chan, W. Dan Powell, Martin P. Harmer, Jentung Ku, Suxing Wu
  • Patent number: 6048394
    Abstract: A method is disclosed for forming a single crystal relaxor based material, including the following steps: providing a seed single crystal plate, providing a first and second polycrystalline structure, bonding the top surface of the seed crystal plate to the outer surface of the first polycrystalline structure, bonding the bottom surface of the seed crystal plate to the outer surface of the second polycrystalline structure, and annealing the bonded structure.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: April 11, 2000
    Assignee: Competitive Technologies of PA, Inc.
    Inventors: Martin P. Harmer, Helen M. Chan, Ho-Yong Lee, Adam M. Scotch, Tao Li, Frank Meschke, Ajmal Khan
  • Patent number: 5282825
    Abstract: A surgical ligaturing and restraining device for small animals comprises an elongated tubular body member (10) having a noose (28) at the front end (18) operable from the rear end (12) of the body. The body front end is fitted with a cap (20) with two holes (22) (24) through its face. The noose is formed by a flexible and elastic cable (26), one end (25) of the cable is looped around passing through the holes in the cap. Said cable end (25) is attached to the cable itself around cable middle portion by attachment means (30). The cable runs through the inside of the body and emerges substantially from the body rear end (12). The body rear end has two short longitudinally extending slots (14) (16), each slot has one extremity open to the rear end. The slots are diametrically opposite each other, dividing the tubular body into two sides (32) (34). One side (32) is made shorter than the opposite side (34 ), so as to facilitate the locking action. The device is applied by placing the noose around an object.
    Type: Grant
    Filed: June 2, 1993
    Date of Patent: February 1, 1994
    Inventors: Kin C. Muck, Helen M. Chan
  • Patent number: 5218928
    Abstract: A device for restraining an avian animal, or other small animals, so as to restrict the movements of its body, while leaving its head, legs, and its rear region exposed for various treatments. The restrainer comprises a substantially flat sheet of pliable material, to which are attached a plurality of fastener members, the fastener members having fastening surfaces adapted for releasable attachment to each other, in conjunction with a pliable strap having fastening surface adapted for releasable attachment to the corresponding fastener members on the restrainer. The sheet is folded into an approximate funnel or truncated cone shape with two openings, and retained in this shape by the engagement of the releasable fastener members.
    Type: Grant
    Filed: September 14, 1992
    Date of Patent: June 15, 1993
    Inventors: Kin C. Muck, Helen M. Chan