Patents by Inventor Randall Gemmen

Randall Gemmen 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: 7159841
    Abstract: This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: January 9, 2007
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Randall Gemmen, Jimmy Thornton, Jeffrey S. Vipperman, William W. Clark
  • Publication number: 20040137300
    Abstract: This paper presents the fabrication and preliminary testing of a novel piezoelectric microvalve. Fabrication has three steps, which are the actuator fabrication, valve body fabrication and assembly of the microvalve. Fabricating an actuator involves cutting piezoelectric and brass beams, gluing the brass and piezoceramic beams into a trimorph sandwich structure, and curing them under pressure at elevated temperatures. Actuators are then wired either by using conductive epoxy or soldering. Valve body parts are constructed from single crystal silicon substrates using deep reactive ion etching (DRIE). DRIE is a subtractive process, whereby a mask is created on the surface of the stock, which will shield the parts that are not to be machined. Refinements in the actuator manufacturing process are made to increase the quality and decrease the fabrication time. Using a photonic probe, tip deflections of the actuators have been tested at various temperature and voltage levels.
    Type: Application
    Filed: November 7, 2003
    Publication date: July 15, 2004
    Inventors: Randall Gemmen, Jimmy Thornton, Jeffrey S. Vipperman, William W. Clark