Detection Performance of Thiourea Sensing layer on Surface Acoustic Wave for CWA monitoring

초록

Due to the recently several reports of chemical warfare agents (CWAs) attacks in our society as well as in military units, the importance of early detection of CWAs has been emphasized. The higher sensivity and proper selectivity of the targeted agent from a surrounding environment is the important performance for the early detection, which indicate that the sensing layer on surface acoustic wave (SAW) is the key factor in CWA detection. In this study, We synthsized the sensitivy Thiourea (TU) based sensing material for detecting the simulants of CWA such as DMMP, TEP, DPGME, ECA, DEP to design the sensitive SAW sensor [1]. The actual SAW sensor with operating frequency at 250 MHz, consisting of an interdigital transducers (IDTs), a delay line, and a reflector on an ST-X quartz substrate was fabricated by lift-off technique. From the experiments using a bubbler type gas feeding system, a designed SAW sensors with TU coating show a relatively good response characteristics and excellent selectivity to CWA simulants. Also the adsorption-desorption time is also dependant on the attached functional group of TU layer, which can indicate that the sensitivity and the selectivity can adjustable by proper slection of functional group for the target agent.