Development of a Room Temperature SAW Methane Gas Sensor Incorporating a Supramolecular Cryptophane A Coating

Sensors

Wen Wang³  Haoliang Hu³  Xinlu Liu³  Shitang He³  Yong Pan¹  Caihong Zhang²  Chuan Dong² 

[1] State Key Laboratory of NBC Protection for Civilian, Yangfang, Changping District, Beijing 102205, China;School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China;State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, No. 21, BeiSiHuan West Road, Beijing 100190, China;

关键词: surface acoustic wave;    methane gas sensor;    cryptophane A;    room temperature;    resonator-oscillator;   

DOI  :  10.3390/s16010073

来源: mdpi

【 摘 要 】

A new room temperature supra-molecular cryptophane A (CrypA)-coated surface acoustic wave (SAW) sensor for sensing methane gas is presented. The sensor is composed of differential resonator-oscillators, a supra-molecular CrypA coated along the acoustic propagation path, and a frequency signal acquisition module (FSAM). A two-port SAW resonator configuration with low insertion loss, single resonation mode, and high quality factor was designed on a temperature-compensated ST-X quartz substrate, and as the feedback of the differntial oscillators. Prior to development, the coupling of modes (COM) simulation was conducted to predict the device performance. The supramolecular CrypA was synthesized from vanillyl alcohol using a double trimerisation method and deposited onto the SAW propagation path of the sensing resonators via different film deposition methods. Experiential results indicate the CrypA-coated sensor made using a dropping method exhibits higher sensor response compared to the unit prepared by the spinning approach because of the obviously larger surface roughness. Fast response and excellent repeatability were observed in gas sensing experiments, and the estimated detection limit and measured sensitivity are ~0.05% and ~204 Hz/%, respectively.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.