ULTRASENSITIVE HIGH-TEMPERATURE SELECTIVE GAS DETECTION USING PIEZOELECTRIC MICROCANTILEVERS

Shih, Wan Y. ; Patil, Tejas ; Zhao, Qiang ; Chiu, Yi-Shi ; Shih, Wei-Heng

Drexel University (United States)

关键词: Temperature Dependence;    Dielectric Materials;    Niobates;    36 Materials Science;    Sensitivity;   

DOI  :  10.2172/833254
RP-ID  :  NONE
RP-ID  :  FG26-02NT41541
RP-ID  :  833254

美国|英语

来源: UNT Digital Library

【 摘 要 】

We have obtained very promising results in the Phase I study. Specifically, for temperature effects, we have established that piezoelectric cantilever sensors could retain their resonance peak strength at high temperatures, i.e., the Q values of the resonance peaks remained above 10 even when the temperature was very close to the Curie temperature. This confirms that a piezoelectric cantilever sensor can be used as a sensor up to its Curie temperature. Furthermore, we have shown that the mass detection sensitivity remained unchanged at different temperatures. For selective gas detection, we have demonstrated selective NH{sub 3} detection using piezoelectric cantilever sensors coated with mesoporous SiO{sub 2}. For high-temperature sensor materials development, we have achieved highly oriented Sr-doped lead titanate thin films that possessed superior dielectric and ferroelectric properties. Such highly oriented films can be microfabricated into high-performance piezoelectric microcantilever sensors that can be used up to 490 C. We have accomplished the goal of Phase I study in exploring the various aspects of a high-temperature gas sensor. We propose to continue the study in Phase II to develop a sensor that is suitable for high-temperature applications using piezoelectrics with a high Curie temperature and by controlling the effects of temperature. The lead titanate based thin film developed in Phase I is good for applications up to 490 C. In phase II, we will develop lithium niobate thin film based cantilevers for applications up to 1000 C.