SGER: Investigation of High Temperature Resonant Gas Sensor

将研究将高灵敏度谐振式气体传感器的运行扩展到更高温度的可行性。为此，Langasite的电学、共振和质量传输特性将被表征为温度、氧分压和阳离子组成的函数。根据这些结果，将要开发的缺陷模型将被用来修饰Langasite，以保持高Q值和成分对高温的稳定性，从而确保高灵敏度。将研究和实施隔离热和应力交叉影响的方法。采用脉冲激光沉积的方法，在不同厚度和不同微观结构的硅锌矿上沉积气敏薄膜(PrxCe1-xO2-？和氧化锌)。灵敏度和响应时间将与薄膜的化学计量比、厚度和颗粒形态相关。对薄膜化学计量比和电阻率与温度和pO2的并行监测将进一步深入了解气-固相互作用。块状和表面声波谐振器件在涂覆适当的物种敏感薄膜时，对各种化学和生物物种表现出极高的灵敏度，但通常仅限于室温操作。在本程序中，我们模拟和研究了在高温和可控气氛中，Langasite的电学和质量输运特性。从这些研究中获得的了解，将使这一多功能谐振传感器平台能够在高温下运行，从而满足交通、工业流程和能源行业对改进传感器的需求。本提案是针对尊敬的同事来信：下一代化学和生物传感器及传感系统[NSF 02-112]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].