Patents by Inventor Rajeshuni Ramesham

Rajeshuni Ramesham 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: 6507187
    Abstract: An ultrasensitive displacement sensing device for use in accelerometers, pressure gauges, temperature transducers, and the like, comprises a sputter deposited, multilayer, magnetoresistive field sensor with a variable electrical resistance based on an imposed magnetic field. The device detects displacement by sensing changes in the local magnetic field about the magnetoresistive field sensor caused by the displacement of a hard magnetic film on a movable microstructure. The microstructure, which may be a cantilever, membrane, bridge, or other microelement, moves under the influence of an acceleration a known displacement predicted by the configuration and materials selected, and the resulting change in the electrical resistance of the MR sensor can be used to calculate the displacement. Using a micromachining approach, very thin silicon and silicon nitride membranes are fabricated in one preferred embodiment by means of anisotropic etching of silicon wafers.
    Type: Grant
    Filed: August 24, 1999
    Date of Patent: January 14, 2003
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John D. Olivas, Bruce M. Lairson, Rajeshuni Ramesham
  • Patent number: 4931763
    Abstract: MnO.sub.2-x thin films (12) exhibit irreversible memory switching (28) with an "OFF/ON" resistance ratio of at least about 10.sup.3 and the tailorability of "ON" state (20) resistance. Such films are potentially extremely useful as a "connection" element in a variety of microelectronic circuits and arrays (24). Such films provide a pre-tailored, finite, non-volatile resistive element at a desired place in an electric circuit, which can be electrically turned OFF (22) or "disconnected" as desired, by application of an electrical pulse. Microswitch structures (10) constitute the thin film element, contacted by a pair of separate electrodes (16a, 16b) and have a finite, pre-selected ON resistance which is ideally suited, for example, as a programmable binary synaptic connection for electronic implementation of neural network architectures. The MnO.sub.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: June 5, 1990
    Assignee: California Institute of Technology
    Inventors: Rajeshuni Ramesham, Anilkumar P. Thakoor, John J. Lambe
  • Patent number: 4839700
    Abstract: A solid-state variable resistance device (10) whose resistance can be repeatedly altered by a control signal over a wide range, and which will remain stable after the signal is removed, is formed on an insulated layer (14), supported on a substrate (12) and comprises a set of electrodes (16a, 16b) connected by a layer (18) of material, which changes from an insulator to a conductor upon the injection of ions, covered by a layer (22) of material with insulating properties which permit the passage of ions, overlaid by an ion donor material (20). The ion donor material is overlaid by an insulating layer (24) upon which is deposited a control gate (26) located above the contacts. In a preferred embodiment, the variable resistance material comprises WO.sub.3, the ion donor layer comprises Cr.sub.2 O.sub.3, and the layers sandwiching the ion donor layer comprise silicon monoxide.
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: June 13, 1989
    Assignee: California Institute of Technology
    Inventors: Rajeshuni Ramesham, Sarita Thakoor, Taher Daud, Aniklumar P. Thakoor