可同步量測溫度及溼度之微機電感測器

Abstract

生活上常見的感測器有溫度計、溼度計、壓力計等，感測器可以說是無所不在。微機電製程與技術的進步，更是將感測器朝向尺寸微小化發展，其中可與微機電製程整合之微感測器如加速計、陀螺儀等，更是受到人們的青睞。 本論文所使用之熱電偶元件為實驗室學長洪家麒所設計，旨在探討將此熱電偶設計作為可同時量測溫度及溼度的感測器之可行性。我們利用微機電技術的Metal MUMPs製程，生產出長度為600 μm及900 μm之熱電偶(Thermocouple)，作為微型感測器，主要原理為席貝克效應(Seebeck Effect)，當熱電偶元件兩端有溫差時，便會產生電動勢，可用柰米伏特計(Nano-Volt Meter)量取電壓。 藉由在不同環境溫度的情況下，量測熱電偶的電阻變化，我們可以得知感測溫度，且加長型熱電偶與重疊型熱電偶的溫度電阻係數分別為9.8 Ω/℃和5.3 Ω/℃。在不同環境溫度與溼度條件下，量測熱電偶元件的輸出電壓，對照透過電阻量測得到的環境溫度，即可求得環境溼度。 由本研究結果可得到，本論文中以微機電製程所生產之熱電偶感測器確實達到驗證同步量測溫度及溼度之可行性。

There are many kinds of sensors in our life, such as thermometers, humidity meters, and pressure sensors, and they are everywhere. Because of the improvement of the micro electro-mechanical fabrication process and technique, the size of sensor has become smaller. The micro sensors which can be compatible with micro electro-mechanical fabrication process, such as accelerometers and gyroscopes, are highly adored by people. The thermocouple device in this thesis is designed by Jia-qi Hong, my former labmate, and is used to explore the feasibility that gauges the measurement of temperature and humidity simultaneously. We use the Metal MUMPs Process to produce the thermocouples which are 600 μm and 900 μm in length. The main working principle is Seebeck Effect: when there is a temperature difference between the two extremities, the voltage comes into existence and could be measured by nano-volt meter. Through gauging the change of the thermocouple resistance at different temperature of environment, we are enabled to measure temperature, and furthermore, the temperature coefficients of resistance of the longer non-overlap thermocouple and overlap thermocouple are 9.8 Ω/℃ and 5.3 Ω/℃. By measuring the output voltage in the different condition of temperature and humidity and referring to the temperature obtained from the measured resistance, we can get the value of the environment humidity. According to this study, the thermocouple sensors achieve the feasibility that can be used in simultaneous measurement of temperature and humidity.