吳政忠臺灣大學:應用力學研究所黃富群Huangg, Fu-ChunFu-ChunHuangg2010-06-022018-06-292010-06-022018-06-292008U0001-3007200817251400http://ntur.lib.ntu.edu.tw//handle/246246/184791近年來，由於氫能源蓬勃發展，使得氫氣感測器的應用層面越趨廣泛，除了用於工業製備上，往後的氫能源車、加氫站等更需要氫感測器來監控其安全。存文獻有關氫敏材料的研究，可分為導電高分子及金屬氧化物兩大類，前者由於對濕度亦極其敏感，使得其應用範圍較為有限。因此，在本論文中選用穩定性高的金屬氧化物為其感測材料。為求發展一種能在室溫下使用、穩定性高、高靈敏度、快速反應、良好的重複性、寬廣的感測範圍、微型化及低成本的氫氣感測器，表面聲波式感測器所具備的須多良好特質可滿足以上需求，故被選為本論文的感測裝置。論文中，首先製作了一組頻率為145 MHz以128P° PYX-LiNbOB3B為基底的表面聲波共振器並結合適當的放大電路構成一震盪器。感測材料為氧化鋅奈米柱，為了使其能在常溫下作用，添加適量的白金當催化器於其上。此外，對於環境中干擾之雜訊諸如溫度及溼度效應，也使用了雙震盪器結構予以消除。最後，將製作之表面聲波式感測器，曝露於不同的濃度的氫氣當中以探討感測器的響應。實驗中，薄膜式感測材料及奈米柱狀之感測材料都做了量測與分析，結果顯示，結合奈米感測材料之表面聲波式感測器在室溫下對氫氣能擁有良好的靈敏度，且不易受外在環境變化的影響。對於氫氣的反應，以白金/氧化鋅奈米柱為氫敏材料更優於以往的導電聚合物聚苯胺。There is a growing demand for developing a sensing system to measure hydrogen not only for industry applications but also for human safety especially in the purpose of hydrogen energy automobile. The sensing materials are including conducting polymers and metal oxide. In this thesis metal oxide ZnO is chosen as sensing material. A good sensor should be characterized by high sensitivity, wide dynamic range, fast response, good reproducibility, small size, and low cost. Surface acoustic wave (SAW) sensing devices are promising candidates to pursue the goals. n this thesis, a 145 MHz oscillator based on 128P° PYX-LiNbOB3 BSAW resonator was fabricated. Dual delay line configuration is employed to eliminate temperature and humidity fluctuations. Because of nanostructure materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, to function as a hydrogen sensor, the Pt coated ZnO nanorods were coated on the delay line of the resonator as sensing film. The SAW sensor is then used to measure various hydrogen concentrations at ppm level. The results showed that the proposed SAW sensor system exhibits fast response, good sensitivity and short-term repeatability at room temperature. The experimental results are batter than the results based on HCl doped polyaniline nanofibers.Table of Contents謝 I文摘要 IIbstract IIIists of Notations IVable of Contents VIIist of Figures IXist of Tables XIhapter 1 Introduction 1-1 Research Motivation 1-2 Categories of Hydrogen Sensors 2-3 Literature Review 4-4 Contents of the Chapters 5hapter 2 Principle of SAW Sensor 8-1 Principles of SAW Gas Sensor 8-1.1 Mass Loading Effect 8-1.2 Acoustoelectric Effect 10 -2 Coupling-of- Modes Model 12-2.1 [ P ] Matrix 13-2.2 Simulation of Two-Port SAW Filter 15 hapter 3 Fabrication of SAW Sensor 23 -1 Fabrication of Pt-coated ZnO Nanorods 23-2 SAW-based Oscillators 24-2.1 Design & Fabrication of the SAW Resonator 25 -2.2 Amplifier Design 28-2.3 Measurement of SAW Oscillator 29-3 Dual Channel Configuration 29hapter 4 Measurement conducted by the SAW Hydrogen Sensor System 44-1Experimental Setup 44-2 Data Acquisition System 45-3 Humidity Test 46-4 Temperature Effect 47-5 Measurement Results of Hydrogen Concentrations 48-5.1 Repeatability 49-5.2 Sensitivity 50-5.3 Noise Analysis 51hapter 5 Conclusions and Future Work 65 -1 Conclusions 65-2 Future Work 66eferences 70ppendix A 74ppendix B 77ppendix C 79application/pdf3825380 bytesapplication/pdfen-US表面聲波震盪器氫氣感測器鋰酸鈮氧化鋅奈米柱白金催化劑靈敏度SAWOscillatorydrogen sensor128°YX-LiNbO3Ptthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/184791/1/ntu-97-R95543058-1.pdf