SGER: Investigation of High Temperature Resonant Gas Sensor

将研究将高灵敏度谐振式气体传感器扩展到高温环境的可行性。为此，langasite（一种对高温稳定的压电材料）的电学、谐振和质量输运性质将被表征为温度、氧分压和阳离子组成的函数。基于这些结果开发的缺陷模型将用于修饰langasite，以便在高温下保持高Q值和成分稳定性，从而确保高灵敏度。将研究和实施隔离热和应力交叉效应的方法。气敏薄膜(PrxCe1-xO2-？采用脉冲激光沉积的方法在langasite表面沉积不同厚度和微观结构的ZnO。灵敏度和响应时间将与薄膜的化学计量、厚度和晶粒形貌相关。平行监测薄膜化学计量学和电阻率随温度和pO2的变化将进一步深入了解气固相互作用。体声波和表面声波谐振装置在涂上适当的物种敏感膜时，对广泛的化学和生物物种表现出异常的敏感性，但通常限于室温操作。在这个程序中，langasite的电和质量输运性质，一种稳定的压电材料，对高温和受控气氛下的高温进行了建模和研究。从这些研究中获得的理解，将使这个多功能谐振传感器平台能够在高温下运行，从而满足运输、工业过程和能源行业对改进传感器的需求。本提案是为回应致同事信：下一代化学和生物传感器和传感系统[nsf 02-112]而提交的。

The feasibility of extending the operation of highly sensitive resonant-based gas sensors to elevated temperatures will be investigated. Towards this end, the electrical, resonant and mass transport properties of langasite, a piezoelectric material stable to elevated temperatures, will be characterized as functions of temperature, oxygen partial pressure and cation composition. The defect model, to be developed and based on these results, will be used to modify langasite in order to maintain high Q values and compositional stability to elevated temperatures thereby insuring high sensitivity. Means for isolating thermal and stress cross effects will be investigated and implemented. Gas sensitive films (PrxCe1-xO2-?, and ZnO) will be deposited on langasite by pulse laser deposition with varying thickness and microstructure. Sensitivity and response time will be correlated to film stoichiometry, thickness and grain morphology. Parallel monitoring of film stoichiometry and resistivity with temperature and pO2 will provide further insights into gas-solid interactions.Bulk and surface acoustic wave resonant devices exhibit exceptional sensitivity to a wide range of chemical and biological species when coated with appropriate species-sensitive films but are typically limited to room temperature operation. In this program, the electrical and mass transport properties of langasite, a piezoelectric material stable to elevated temperatures, are modeled and investigated to elevated temperatures and in controlled atmospheres. Understanding gained from these studies, will enable the operation of this multifunctional resonant sensor platform to elevated temperatures and thereby address the need for improved sensors in the transportation, industrial process and energy industries. This proposal was submitted in response to the Dear Colleague Letter: Next Generation Chemical and Biological Sensors and Sensing Systems [nsf 02-112].