吳政忠臺灣大學：應用力學研究所王榮德Wang, Rung-DeRung-DeWang2007-11-292018-06-292007-11-292018-06-292007http://ntur.lib.ntu.edu.tw//handle/246246/62535無論是基於人體舒適的考量，或是在醫療、化學、農業等許多領域中環境的控管，相對濕度及溫度的控制一直具有龐大的需求。將感測器結合無線傳輸能力可提供量測的便利性，並降低監測系統成本。傳統上一般感測器如欲達成無線量測的要求，必須將其與無線射頻模組結合，導致感測器成本提高、使用壽命更受制於電池。為了減少成本並增加感測器壽命，具備同步溫度及濕度量測功能之被動式無線感測器便因應而生。 在本論文中，藉由整合中心頻率為433MHz、128˚ YX-LiNbO3為基底之表面聲波式標籤、熱敏電阻和電阻式濕度感測器，阻抗加載型複合式表面聲波感測器已成功實現。此一感測器架構提供了許多引人注目的優點，例如：無線感測，被動式運作，以及尺寸縮小等。 本文首先利用耦合模型理論來設計表面聲波式標籤之參數，並預測其頻率響應。接著，由於以樟腦磺酸為掺雜物之聚苯胺奈米纖維合成容易，同時在室溫下具有穩定表現，此聚苯胺奈米纖維便應用於濕度感測層以提高電阻式濕度感測器之靈敏度表現。最後，將製作之阻抗加載型複合式表面聲波感測器置之於實驗量測腔體中，並以不同的相對溼度及溫度環境來檢驗探討感測器的響應。實驗結果顯示，在不同的溫濕度環境下，感測器皆具有良好的線性度及靈敏度。The control of relative humidity (RH) and ambient temperature is required for a broad spectrum of human comfort, medical instrument, chemical industry, agriculture, and etc. To reduce cost and increase lifetime, a passively wireless sensor which is capable of measuring relative humidity and ambient temperature should be developed to meet this demand. In this thesis, an impedance loaded SAW hybrid sensor is successfully accomplished by integrating a 433MHz 128˚ YX-LiNbO3 based SAW tag with external sensors such as thermistor and resistive RH sensor. The combination exhibits attractive advantages, such as wireless sensing, passive operation, and size minimization. First, the coupling-of-modes model was employed to design the SAW tag and predict its frequency response. To enhance the sensitivity of the resistive RH sensor, CSA-doped polyaniline nanofibers were utilized as sensitive film due to its easy synthesis and stable performance. Finally, the hybrid sensor was constructed and measured to evaluate performances. The results indicate our SAW hybrid sensor exhibits good linearity and high sensitivity.Acknowledgements I Chinese Abstract II Abstract III Lists of Notations IV Table of Contents VII List of Figures IX List of Tables XI Chapter 1 Introduction 1 1-1 Research Motivation 1 1-2 Classification of Humidity and Temperature Sensors 2 1-2.1 Humidity Sensors 2 1-2.2 Temperature Sensors 4 1-3 Literature Review 5 1-4 Contents of the Chapters 7 Chapter 2 Analysis of SAW Hybrid Sensor 11 2-1 Coupling-of-Modes Model 11 2-1.1 First Order Wave Equations 12 2-1.2 Propagation Loss 14 2-1.3 Electrode Reflections 15 2-1.4 Transduction Coupling 19 2-1.5 [P] Matrix 22 2-2 Coupling-of- Modes Parameters 27 2-2.1 Average Surface Acoustic Wave Velocity Shift 27 2-2.2 Reflection Coefficient 29 2-2.3 Transduction Coefficient 31 2-2.4 Electrode Resistance and Capacitance 32 2-2.5 Attenuation Coefficient 33 2-3 Simulation of SAW Hybrid Sensor 34 2-3.1 IDT Type Reflector 34 2-3.2 Impedance Loaded Reflector 35 2-3.3 Frequency Response of SAW Hybrid Sensor 36 Chapter 3 Setup of SAW Sensor System 48 3-1 Working Principle of SAW Hybrid Sensor 48 3-2 Sensor Fabrication 49 3-2.1 Fabrication of the SAW Tag 49 3-2.2 Fabrication of the Resistive RH Sensor 52 3-3 Deposition of Nanomaterial Sensing Layer 54 3-3.1 Selection of Sensing Film 54 3-3.2 Synthesis of CSA-doped Polyaniline Nanofibers 56 3-4 Experiment Setup 58 3-4.1 Wireless Transceiver System 58 3-4.2 Temperature-Controlled Gas Flow System 59 Chapter 4 Measurement Results 74 4-1 Signal Processing Techniques 74 4-2 Measurement of Impedance Loaded Sensors 76 4-2.1 Measurements of Resistive RH Sensor toward Various Relative Humidity 76 4-2.2 Measurements of Thermistor toward Different Temperature 78 4-3 Measurements of SAW Hybrid Sensor 79 4-3.1Humidity Response 80 4-3.2 Temperature Response 82 Chapter 5 Conclusions and Future Perspectives 92 5-1 Conclusions 92 5-2 Future Perspectives 93 References 942581970 bytesapplication/pdfen-US表面聲波無線被動式阻抗相對濕度聚苯胺奈米纖維Surface acoustic waveWirelessPassiveImpedanceRelative humidityPolyanilineNanofiberthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/62535/1/ntu-96-R94543020-1.pdf