Patents by Inventor Ramji S. Lakshmanan

Ramji S. Lakshmanan 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).

  • Asymmetric sensor
    Patent number: 10139270
    Abstract: An asymmetric sensor having asymmetric electrodes and/or being asymmetrically anchored provides enhanced sensitivity. In example embodiments, part of the electrode on a sensor is etched or removed resulting in enhanced mass-change sensitive resonant modes. In another example embodiment, a sensor is anchored asymmetrically, also resulting in enhanced mass-change sensitive resonant modes. By asymmetrically anchoring a piezoelectric portion of a sensor, resonant bending modes of the sensor can be measured electrically without external instrumentation. Modifying the electrode of a piezoelectric cantilever enables expression of mass-change sensitive resonant modes that normally do not lend themselves to electrical measurement.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: November 27, 2018
    Assignee: Drexel University
    Inventors: Rajakkannu Mutharasan, Blake N. Johnson, Ramji S. Lakshmanan, Harsh Sharma
  • Detection and measurement of mass change using an electromechanical resonator
    Patent number: 8809065
    Abstract: A change in impedance of a electromechanical resonating sensor is utilized to detect and/or measure a change in mass accumulated on the sensor. The impedance is monitored at a fixed frequency. The fixed frequency may be at or near the resonance frequency of the sensor. In various configurations, the sensor comprises a quartz crystal microbalance sensor or a piezoelectric cantilever sensor.
    Type: Grant
    Filed: May 19, 2010
    Date of Patent: August 19, 2014
    Assignee: Drexel University
    Inventors: Rajakkannu Mutharasan, Sen Xu, Blake N. Johnson, Harsh Sharma, Ramji S. Lakshmanan
  • ASYMMETRIC SENSOR
    Publication number: 20130205902
    Abstract: An asymmetric sensor having asymmetric electrodes and/or being asymmetrically anchored provides enhanced sensitivity. In example embodiments, part of the electrode on a sensor is etched or removed resulting in enhanced mass-change sensitive resonant modes. In another example embodiment, a sensor is anchored asymmetrically, also resulting in enhanced mass-change sensitive resonant modes. By asymmetrically anchoring a piezoelectric portion of a sensor, resonant bending modes of the sensor can be measured electrically without external instrumentation. Modifying the electrode of a piezoelectric cantilever enables expression of mass-change sensitive resonant modes that normally do not lend themselves to electrical measurement.
    Type: Application
    Filed: July 7, 2011
    Publication date: August 15, 2013
    Applicant: Drexel University
    Inventors: Rajakkannu Mutharasan, Blake N. Johnson, Ramji S. Lakshmanan, Harsh Sharma
  • DETECTION AND MEASUREMENT OF MASS CHANGE USING AN ELECTROMECHANICAL RESONATOR
    Publication number: 20100297687
    Abstract: A change in impedance of a electromechanical resonating sensor is utilized to detect and/or measure a change in mass accumulated on the sensor. The impedance is monitored at a fixed frequency. The fixed frequency may be at or near the resonance frequency of the sensor. In various configurations, the sensor comprises a quartz crystal microbalance sensor or a piezoelectric cantilever sensor.
    Type: Application
    Filed: May 19, 2010
    Publication date: November 25, 2010
    Applicant: DREXEL UNIVERSITY
    Inventors: Rajakkannu Mutharasan, Sen Xu, Blake N. Johnson, Harsh Sharma, Ramji S. Lakshmanan