Patents by Inventor Rolf E. Hummel

Rolf E. Hummel 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: 7368292
    Abstract: A system and method for identifying explosive or other target materials includes the steps of irradiating a first location and a second location spaced apart from the first location from a sample suspected of including explosives with ultraviolet, visible or infrared light, measuring reflected light emanated from the first sample location (R1) and reflected light emanated from the second sample location (R2), and calculating a normalized difference in reflectivity (?R/ R), wherein R=(R1+R2)/2 is an average reflectivity. A differential reflection spectrum (DRS) is then generated for the sample where ?R=R2?R1 is the difference of the reflectivities of the first and the second sample location. One or more explosives if present are identified in the sample based on comparing the DRS for said sample to at least one reference DRS.
    Type: Grant
    Filed: April 11, 2006
    Date of Patent: May 6, 2008
    Assignee: University of Florida Research Foundation, Inc.
    Inventors: Rolf E. Hummel, Ann Marie Fuller, Claus Schollhorn, Paul H. Holloway
  • Patent number: 7250729
    Abstract: The subject invention pertains to a method of spark processing silicon and resulting materials. The subject invention also relates to electroluminescent devices incorporating the materials produced by the subject method. The subject method for spark-processing can enhance the EL output, as compared with conventional spark-processed (sp) silicon. The enhancement of EL output can be due, at least in part, to increasing the light emitting area. The subject method can smooth the sp surface, so as to allow more complete coverage of the sp area with a continuous, semitransparent, conducting film. The smoothening of the sp surface can be accomplished by, for example, introducing into the spark plasma a volatile liquid, such as methanol, ethanol, acetone, in which particles can be suspended and/or in which a heavy ion salt is dissolved. The particles preferably float in the volatile liquid, rather than settle quickly. In a specific embodiment, silicon particles in the range of about 0.
    Type: Grant
    Filed: July 15, 2005
    Date of Patent: July 31, 2007
    Assignee: University of Florida Research Foundation, Inc.
    Inventors: Nigel D. Shepherd, Rolf E. Hummel
  • Patent number: 6955745
    Abstract: The subject invention pertains to a method of spark processing silicon and resulting materials. The subject invention also relates to electroluminescent devices incorporating the materials produced by the subject method. The subject method for spark-processing can enhance the EL output, as compared with conventional spark-processed (sp) silicon. The enhancement of EL output can be due, at least in part, to increasing the light emitting area. The subject method can smooth the sp surface, so as to allow more complete coverage of the sp area with a continuous, semitransparent, conducting film. The smoothening of the sp surface can be accomplished by, for example, introducing into the spark plasma a volatile liquid, such as methanol, ethanol, acetone, in which particles can be suspended and/or in which a heavy ion salt is dissolved. The particles preferably float in the volatile liquid, rather than settle quickly. In a specific embodiment, silicon particles in the range of about 0.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: October 18, 2005
    Assignee: University of Florida Research Foundation, Inc.
    Inventors: Nigel D. Shepherd, Rolf E. Hummel
  • Patent number: 6469605
    Abstract: The present invention pertains to methods for altering the magnetic properties of materials and the novel materials produced by these methods. The methods of this invention concern the application of high voltage, high frequency sparks to the surface of materials in order to alter the magnetic properties of the materials. Specially, the present invention can be applied to diamagnetic silicon to produce ferromagnetic spark-processed silicon.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: October 22, 2002
    Assignee: University of Florida
    Inventors: Jonathan A. Hack, Rolf E. Hummel, Matthias H. Ludwig
  • Publication number: 20020003383
    Abstract: The present invention pertains to methods for altering the magnetic properties of materials and the novel materials produced by these methods. The methods of this invention concern the application of high voltage, high frequency sparks to the surface of materials in order to alter the magnetic properties of the materials. Specially, the present invention can be applied to diamagnetic silicon to produce ferromagnetic spark-processed silicon.
    Type: Application
    Filed: June 1, 2001
    Publication date: January 10, 2002
    Inventors: Jonathan A. Hack, Rolf E. Hummel, Matthias H. Ludwig
  • Patent number: 6264801
    Abstract: The present invention pertains to methods for altering the magnetic properties of materials and the novel materials produced by these methods. The methods of this invention concern the application of high voltage, high frequency sparks to the surface of materials in order to alter the magnetic properties of the materials. Specially, the present invention can be applied to diamagnetic silicon to produce ferromagnetic spark-processed silicon.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: July 24, 2001
    Assignee: University of Florida
    Inventors: Jonathan A. Hack, Rolf E. Hummel, Matthias H. Ludwig
  • Patent number: 6113746
    Abstract: Methods for altering the magnetic properties of materials and the novel materials produced by these methods. The methods concern the application of high voltage, high frequency sparks to the surface of materials in order to alter the magnetic properties of the materials. Specificaly this method can be applied to diamagnetic silicon to produce ferromagnetic spark-processed silicon.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: September 5, 2000
    Assignee: University of Florida
    Inventors: Jonathan A. Hack, Rolf E. Hummel, Matthias H. Ludwig
  • Patent number: 5843811
    Abstract: A method of forming a crystalline thin film from an amorphous semiconductor thin film such as amorphous silicon, by providing a generally planar nucleation inducing member, such as a crystalline silicon wafer, having a number of micro-scale surface contact points and with a hardness equal to or greater than the hardness of the amorphous semiconductor thin film, contacting under pressure the surface contact points of the nucleation inducing member with the exposed surface of the amorphous thin film to form an assembly, annealing the assembly at between 300 to 700 degrees C. for 1 to 24 hours to crystallize the amorphous thin film, and removing the nucleation inducing member.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: December 1, 1998
    Assignee: University of Florida
    Inventors: Rajiv K. Singh, Rolf E. Hummel, Soon-Moon Jung
  • Patent number: 5597621
    Abstract: A method for the manufacture of a photoluminescing layer on a normally non-photoluminescing semiconductor substrate, such as a porous silicon layer created on a silicon substrate, by treating the surface of the substrate with a relatively high energy, pulsed laser beam.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: January 28, 1997
    Assignee: University of Florida
    Inventors: Rolf E. Hummel, Matthias H. Ludwig, Martin Vala
  • Patent number: 5397429
    Abstract: A high frequency, high voltage spark generator is used to create a large number of sparks to erode the surface of a silicon wafer to a depth of up to 100 microns. After a sufficient amount of erosion has occurred, but prior to any macro-scale removal of material, the surface layer of the silicon wafer becomes porous and photoluminescing. The method can be performed in ambient atmosphere and temperature, or in specific gas atmospheres and at different temperatures. The method produces photoluminescing porous silicon layers on p-type, n-type, low-doped, high-doped or undoped silicon wafers.
    Type: Grant
    Filed: September 14, 1993
    Date of Patent: March 14, 1995
    Assignee: University of Florida
    Inventors: Rolf E. Hummel, Sung-Sik Chang