Technology Transfer SSC Pacific
Fluctuation Enhanced Chemical Sensing

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A chemical and gas sensing system and method that uses fluctuation enhanced sensors to provide improved sensitivity and selectivity

The U.S. Navy seeks to commercialize U.S. Patents 7,524,460 (System and method of molecule counting using fluctuation enhanced sensors), 7,286,942 (System and method of fluctuation enhanced  gas-sensing using saw devices); and 7,680,607 (System and method for gas recognition by analysis of bi-spectrum functions).


Homeland defense, including anti-terrorist efforts, requires highly selective, sensitive, and reliable detection of harmful gaseous agents. Intensive research has resulted in the use of chemical and biological sensor elements for the development of electronic noses (for gas sensing) and electronic tongues (for fluid sensing). The most sensitive and reliable method presently available for gas sensing utilizes surface acoustic wave (SAW) devices. However, current applications of this technology measure
only the average resonant frequency, resulting in lack of selectivity, and are highly susceptible to inaccuracies due to changes in temperature. Therefore, there is a need for a highly selective, sensitive and reliable method of gas-sensing that is also less susceptible to inaccuracies due to changes in temperature.

The Technology

The interaction between a chemical sensor and the molecules it detects is always
a dynamic stochastic process. Fluctuations that result from this interaction carry a “stochastic fingerprint” of the chemicals with which the sensor interacts. Microscopic fluctuations around the mean value of the sensor signal contain much more information than the mean value alone. Fluctuation Enhanced Sensing (FES) uses sophisticated statistical analysis tools to incorporate this additional information. The system hardware consists of a small array of sensors, a low-noise preamplifier, a digitizer, and a computer. The FES algorithms process the time series produced by the digitizer. The software component comprises pattern generation and recognition algorithms, a small pattern database, and a graphical user interface or software interface to a communication grid and/or other modules.

Key Benefits

  • Improves both sensitivity and selectivity of current sensor methods by utilizing information currently ignored
  • Capable of simultaneous concentration measurement and agent classification  both features currently unavailable with existing methods
  • Capable of operating under wider temperature range than existing methods
  • Lower false alarm rate
  • Reduced energy and decreased size requirements
  • Development Status

  • U.S. Patents issued: 7,524,460, 7,286,942, 7,680,607
  • DoD 5000 Series Technology Readiness Level 3: Analytical and experimental critical function and/or characteristic proof of concept
  • Sensor, data acquisition component and software prototypes completed
  • Undergoing Army SBIR Phase II laboratory testing
  • For more information on technology transfer, please contact us at (619) 5535118 or email
    SD 863, August 2009. SSC Pacific, San Diego, CA 921525001. Approved for public release; distribution is unlimited.

    SSC Pacific
    Updated: 11/7/2011 10:42 AM EST   Published