Development of MEMS-based thermal sensors for gas sensing and vacuum pressure measurements**

气体传感器有助于防止危险气体的传播，并在有潜在有害物质风险的地方发挥重要作用，特别是在工业流程和制造厂。化学气体传感器是基于气体与敏感材料之间的化学反应，导致探测器材料的电导率发生变化。最近，制造各种传感器设备的蒙特利尔第一传感器公司开发了一种基于MEMS的热传感器，用于测量气体的压力和流量，有几个工业应用，特别是在医疗和制药领域。传感器的进一步商业化需要改进其功能。由于该装置的选择性低和分辨率有限，该传感器不能用于分析含有两种以上组分的气体混合物，也不能用于需要检测到少量某些气体的应用。另一方面，该设备对湿度、温度的变化非常敏感。为了提供进一步将该设备商业化的机会，需要对该设备的设计和特性进行广泛的改进。开发热敏气体传感器的信号处理算法和先进的操作模式，包括在不同过热温度下的操作、温度漂移的补偿、传感元件内部参数的漂移和降噪程序，将提高设备的性能。改进的热敏气体传感器的开发需要先进的工程专业知识和先进的实验装置，能够精确调整各种气体混合物，并将环境压力从1个大气压控制到1 mTorr以下。传感器的特性和电子电路的设计将在康科迪亚大学欧洲经委会系的微/纳米设备实验室进行，合作的工程师和第一传感器公司的专业知识*

Gas sensors helps to prevent the spread of hazardous gases and play important roles in places with the risk of potentially harmful substances specifically in industrial processes and manufacturing plants. Chemical gas sensors are based on chemical reaction between gas and sensing materials, resulting in change of conductivity of the detector materials. Recently, First Sensor Corp, a company in Montreal fabricating various sensor devices, has developed a MEMS-based thermal sensor for pressure and flow measurements of gases with several industrial applications in particular in medical and pharmaceutical areas. Further commercialization of the sensor requires improvement of its function. Due to the low selectivity and limited resolution of the device, the sensor cannot be used in analyzing gas mixtures containing more than two components or in applications where small concentration of certain gases should be detected. On the other hand, the device is very sensitive to changes in moisture, temperature. To provide opportunities to further commercialize the device, extensive improvement in design and characteristics of the device are required. Development of signal processing algorithms and advanced operating modes for the thermal gas sensor including operation at different overheating temperatures, compensation of temperature drift, drift of internal parameters of the sensing element and noise reduction routines will improve performance of the device. Development of an improved thermal gas sensors requires advanced engineering expertise and advanced experimental setup with possibility to adjust accurately various gas mixtures and control ambient pressure from 1 atmosphere to less than 1mTorr. The characterization of the sensor and design of its electronics circuitry will be performed in the laboratories of Micro/Nano devices in ECE department at Concordia University with collaboration of engineers and expertise of First Sensor Corp. **************