以微機電製程製作之溫度、溼度、氣壓與氣體分壓感測器

Abstract

感測器在我們的生活中無所不在，像是溫度計、溼度計、氣體感測器等。近年來隨著微機電製程技術快速發展下，感測器朝向微小化與系統化發展，因此可與微機電件元件整合的微感測器，因其輕、薄、短、小的優點，受到人們的重視與喜愛。 本研究的熱電偶元件為實驗室學長洪家麒根據席貝克效應所製作，設計成四種型態的熱電偶元件:重疊型熱電偶、非重疊型熱電偶、非重疊加長型熱電偶與非重疊對稱型熱電偶。本研究針對熱電偶元件進行基本工作效能實驗、定溫調壓實驗、定壓調溫實驗、定溫調二氧化碳分壓實驗、定二氧化碳分壓調溫實驗、定相對溼度調溫實驗、定溫調相對溼度實驗與定蒸氣壓調溫實驗，探討其作為感測器的效果。 研究的實驗結果，三種型態熱電偶：重疊型熱電偶、非重疊對稱型熱電偶與非重疊加長型熱電偶，在基本工作效能實驗，輸出電壓與漆包線加熱電流都呈正相關；在定溫調壓下，輸出電壓與環境真空度都呈正相關；在定壓調溫下，輸出電壓與環境溫度都呈正相關；在定溫調二氧化碳分壓下，輸出電壓與二氧化碳分壓都呈負相關；在定二氧化碳分壓調溫下，輸出電壓與環境溫度都呈正相關；在定相對溼度調溫下，輸出電壓與環境溫度都呈正相關。而在定溫調相對溼度下，非重疊對稱型熱電偶與非重疊加長型熱電偶輸出電壓與腔體環境相對溼度呈負相關；重疊型熱電偶以蒸氣壓74 mmHg附近為轉折點，在蒸氣壓為74 mmHg之前，輸出電壓與腔體環境相對溼度呈正相關；在蒸氣壓為74 mmHg之後，輸出電壓與腔體環境相對溼度呈負相關。在定蒸氣壓調溫實驗，輸出電壓與環境溫度都呈正相關。 根據實驗結果，熱電偶元件可以多功能感測環境溫度、相對溼度、氣壓與不同二氧化碳分壓的能力。

Sensor is everywhere in our lives such as the thermometer, the hygrometer and the gas sensor. Recently, with the rapid development of micro electro-mechanical technique, the sensor becomes smaller and systematic. Because micro-sensor compatible with micro electro-mechanical devices has advantages of light, thin, short, and small. Therefore People pay attention to it gradually. Jia-qi Hong a former laboratory member had designed four types of thermocouple devices based on Seebeck effect: overlap thermocouple, non-overlap thermocouple, longer non-overlap thermocouple and symmetric non-overlap thermocouple. This study proceeded basic efficiency experiment, fixed temperature to adjust pressure experiment, fixed pressure to adjust temperature experiment, fixed temperature to adjust carbon dioxide partial pressure experiment, fixed carbon dioxide partial pressure to adjust temperature experiment, fixed relative humidity to adjust temperature experiment, and fixed temperature to adjust relative humidity experiment. Thses experiments were used to test the effect of thermocouple devices as the sensor. According to the result of experiments, the output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with heating current in basic efficiency experiment. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with environmental vacuum degree under fixed temperature to adjust pressure experiment. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with environmental temperature in fixed pressure to adjust temperature experiment. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are negative correlation with carbon dioxide partial pressure in fixed temperature to adjust carbon dioxide partial pressure experiment. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with environmental temperature in fixed carbon dioxide partial pressure to adjust temperature experiment. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with environmental temperature in fixed relative humidity to adjust temperature experiment. The output voltage of symmetric non-overlap thermocouple and longer non-overlap thermocouple are negative correlation with environmental relative humidity in fixed temperature to adjust relative humidity experiment. Under fixed temperature to adjust relative humidity experiment, the vapor pressure of 74mmHg is turning point in overlap thermocouple. Before the vapor pressure is 74mmHg, the output voltage of overlap thermocouple is positive correlation with environment relative humidity. Aftere the vapor pressure is 74mmHg, the output voltage of overlap thermocouple is negative correlation with environment relative humidity. The output voltage of overlap thermocouple, symmetric non-overlap thermocouple and longer non-overlap thermocouple are positive correlation with environmental temperature in fixed vapor pressure to adjust temperature experiment. According to the experimental results, the thermocouple devices can be multi-function to sense the environmental temperature, relative humidity, pressure and carbon dioxide partial pressure.