• DocumentCode
    1865481
  • Title

    Simultaneous and wireless measurement of CO2 and NO2 using a saw reflective delay line

  • Author

    Lim, Chunbae ; Yang, Sangsik ; Lee, Keekeun

  • Author_Institution
    Dept. of Electron. Eng., Ajou Univ., Suwon, South Korea
  • fYear
    2009
  • fDate
    21-25 June 2009
  • Firstpage
    995
  • Lastpage
    998
  • Abstract
    A 440 MHz wireless and passive surface acoustic wave (SAW) based micro-sensor was developed on a 41deg YX LiNbO3 piezoelectric substrate for simultaneous measurement of CO2 and NO2. The developed sensor consists of a SAW reflective delay lines structured by an interdigital transducer (IDT), ten reflectors, CO2 sensitive film (Teflon AF 2400), and NO2 sensitive film (Indium Tin Oxide). The coupling of mode (COM) modeling was conducted to determine optimal device parameters prior to fabrication. According to simulation results, the device was fabricated and then wirelessly measured using the network analyzer. The measured reflective coefficient S11 in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. From the experimental results, high selectivity and sensitivity were observed in each concentration of gases. The obtained sensitivity was 2.12deg/ppm for CO2 and 55.4deg/ppm for NO2. Temperature compensation was performed during sensitivity evaluation process.
  • Keywords
    carbon compounds; gas sensors; interdigital transducers; lithium compounds; microsensors; network analysers; nitrogen compounds; piezoelectric devices; surface acoustic wave delay lines; surface acoustic wave sensors; CO2; LiNbO3; NO2; SAW reflective delay line; SAW sensor; coupling-of-mode modeling; gas sensor; interdigital transducer; microsensor; network analyzer; piezoelectric sensor; reflective coefficient; sensitivity evaluation process; temperature compensation; wireless measurement; Acoustic measurements; Acoustic sensors; Acoustic waves; Delay lines; Gas detectors; Optical films; Piezoelectric transducers; Substrates; Surface acoustic waves; Wireless sensor networks; Batteryless; CO2; NO2; SAW (surface acoustic wave); multi-gas sensor; reflective delay line; wireless;
  • fLanguage
    English
  • Publisher
    ieee
  • Conference_Titel
    Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International
  • Conference_Location
    Denver, CO
  • Print_ISBN
    978-1-4244-4190-7
  • Electronic_ISBN
    978-1-4244-4193-8
  • Type

    conf

  • DOI
    10.1109/SENSOR.2009.5285955
  • Filename
    5285955
    • Link To Document
    https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=1865481