Gas sensing through evanescent coupling of spoof surface acoustic waves

ÇİÇEK A., ARSLAN Y., Trak D., Okay F. C., KAYA O. A., KÖRÖZLÜ N., ...Daha Fazla

SENSORS AND ACTUATORS B-CHEMICAL, cilt.288, ss.259-265, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 288
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1016/j.snb.2019.02.119
  • Dergi Adı: SENSORS AND ACTUATORS B-CHEMICAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.259-265
  • Anahtar Kelimeler: Spoof surface acoustic wave, Phononic crystal, Evanescent coupling, Gas sensing, CARBON-DIOXIDE, PHONONIC CRYSTAL, FLUORESCENT CHEMOSENSOR, CO2, SENSOR, HUMIDITY, WATER
  • İnönü Üniversitesi Adresli: Evet

Özet

An ultrasonic gas sensor based on evanescent coupling of spoof surface acoustic waves between two surface phononic crystals containing trapezoidal grooves on rigid slabs is theoretically and experimentally demonstrated. Sensing properties for carbon dioxide in dry air at 25 degrees C and 760 Torr are investigated as an example. Band structure analyses reveal two spoof surface acoustic wave bands with opposite parities when the separation of surface phononic crystals is 1.5 times the periodicity of grooves. The beat length varies with frequency and carbon dioxide volume fraction, where the increase of the latter results in red shift of a sharp intense output peak at 59.69 kHz at a rate of 17.70 mHz/ppm and 16.20 mHz/ppm for carbon dioxide volume fractions up to 10,000 ppm, as measured through Finite-Element Method simulations and experiments, respectively. Gas sensing can also be achieved by measuring the output acoustic intensity at constant frequency, which exhibits a steep decrease with carbon dioxide volume fraction up to 2000 ppm.