本研究之表面聲波氣體感測器(Surface Acoustic Wave Gas Sensor)是使用128°YX-LiNbO3為壓電基板，搭配黃光微影製程與感測薄膜發展出高靈敏度的表面聲波氣體感測器。表面聲波氣體感測器根據頻率飄移效應，當有質量附著於感測薄膜時會導致表面聲波中心頻率下降。
本實驗首先以熱脫附氣相層析質譜儀(Thermal Desorption-Gas Chromatography-Mass Spectrometer, TD-GC-MS)分析茶葉內有多種化合物，並透過文獻及討論，確立了9種化合物(Hexenal、Geraniol、Linalool、Methyl salicylate、D-Limonene、Ocimene、Nonanal、Decanal、Benzaldehyde)為影響茶葉氣味的重要化合物；並再次以TD-GC-MS分析攪拌前與攪拌後共六個點位之茶葉(BS1、AS1、BS2、AS2、BS3、AS3，BS=Before Shaking，AS=After shaking)，得到六點位間各化合物濃度變化之趨勢。
接著利用葡萄糖(Glucose)與B-環狀糊精（B-cyclodextrin, B-CD）作為感測薄膜，以表面聲波氣體感測器量測上述9種茶葉重要化合物之單一標準溶液，得到頻率變化後並根據Wohltjen’s equation進行歸一化處理，經歸一化後可得每單位重的薄膜對茶葉氣味的吸附能力，計算出兩種感測薄膜對9種茶葉重要化合物之靈敏性高低。
最後，同樣以Glucose與B-CD作為感測薄膜，再次利用表面聲波氣體感測器量測六個點位之茶葉，觀察到其各點位間頻率變化趨勢與上述TD-GC-MS及單一標準溶液實驗之量測結果有很高的關聯性，本研究將探討其中之相關性與趨勢。
本研究之實驗參數設定與方法，可以將九成的三重複實驗其之間的變異係數維持於10 %內，代表表面聲波氣體感測器與兩感測薄膜的搭配，有很高的實驗再現性。
茶葉製程中，判斷茶葉氣味並決定攪拌的時機點相當重要，可以影響最後茶葉泡出來之風味，本研究利用表面聲波氣體感測器及熱脫附氣相層析質譜儀進行茶葉氣味分析，並探討其中之相關性與趨勢，希望藉此發展出簡單、快速並能輔助茶農判斷攪拌時機點之系統，穩定茶葉製程之品質。

In this study, 128°YX-LiNbO3 was used as the piezoelectric substrate, combined with the lithography process and sensing film to develop a highly sensitive surface acoustic wave gas sensor (SAW gas sensor). According to the frequency drift effect, when there is mass attached to the sensing film on SAW gas sensor, the central frequency of surface acoustic wave will decrease.
In this experiment, a variety of compounds in tea were firstly analyzed by Thermal Desorption-Gas Chromatography-Mass Spectrometer (TD-GC-MS).Including Linalool, Methyl salicylate, D-Limonene, Ocimene, Nonanal, Decanal, Benzaldehyde which are important compounds that affect the smell of tea leaves; and again, TD-GC-MS was used to analyze the tea leaves at six points before and shaking (BS1, AS1, BS2, AS2, BS3, AS3, BS=Before Shaking, AS=After shaking), the trend of the concentration change of each compound between the six points was obtained.
Then, using glucose and B-cyclodextrin (B-CD) as the sensing film, the surface acoustic wave gas sensor was used to measure the single standard solution of the above-mentioned 9 important tea compounds, after obtaining the frequency change(Hz), it is normalized according to Wohltjen's equation. After normalization, the adsorption capacity of the film per unit weight to tea odor can be obtained, and the sensitivity of the two sensing films to 9 important tea compounds can be calculated. During the adsorption process of real tea leaves, the contribution of each tea compound to the frequency change was measured.
Finally, Glucose and B-CD were also used as sensing films, and the surface acoustic wave gas sensor was used to measure the tea leaves at six points again. It is observed that the frequency change trend of each point has a high correlation with the measurement results of the above TD-GC-MS and single standard solution experiments. The measurement results of the solution experiments are highly correlated. This study will explore these correlations and trends.
In the tea making process, it is very important to judge the smell of tea leaves and determine the timing of shaking, which can affect the flavor of the final tea leaves. In this study, surface acoustic wave gas sensor and TD-GC-MS were used to analyze the smell of tea leaves. By exploring the correlations and trends, a simple and rapid system for judging the timing of shaking can be developed to assist tea farmers and stabilize the quality of the tea process.

摘要 i
Abstract ii
圖目錄 vii
表目錄 x
1.緒論 1
1.1研究動機 1
1.2研究目標 2
1.2.1利用熱脫附氣相層析質譜儀分析茶葉氣味 2
1.2.2 利用表面聲波氣體感測器測量茶葉主要化合物之單一標準溶液 2
1.2.3 利用表面聲波氣體感測器測量茶葉氣味 2
2.文獻回顧 4
2.1 樣品採集 4
2.1.1 固相微萃取 (Solid-phase microextraction) 4
2.1.2 熱脫附法 (Thermal desorption) 5
2.2 氣體分析方法 6
2.2.1 傅立葉轉換紅外光譜 (Fourier Transform Infrared Spectroscopy) 6
2.2.2 火焰電離檢測器 (Flame Ionization Detector, FID) 7
2.2.3 氣相層析質譜儀系統 (Gas chromatography–mass spectrometry) 7
2.3 氣體感測器介紹 9
2.3.1 半導體氣體感測器 (Metal oxide semiconductor gas sensor) 10
2.3.2 紅外線氣體感測器 (Infrared gas sensor) 10
2.3.3 石英晶體微量天秤 (Quartz Crystal Microbalance，QCM) 11
2.3.4 表面聲波氣體感測器 (Surface acoustic wave gas sensor) 11
2.3.5 各種氣體感測器之比較 12
2.4 茶葉氣味成份分析及感測之相關文獻 13
3.茶葉之標準製程與表面聲波之基本理論 15
3.1 茶葉之標準製程 15
3.2 表面聲波 16
3.3 壓電效應 18
3.4 壓電材料基板 20
3.4.1 壓電基板的材料種類及參數 20
3.4.2 壓電基材之傳遞損失 23
3.5 指叉電極轉換器(Interdigital Transducers) 25
4. TD-GC-MS對茶葉六個點位之分析 28
4.1 TD-GC-MS對茶葉中化合物之分析 30
4.2 TD-GC-MS對六個點位之茶葉量測結果 32
5.表面聲波氣體感測晶片設計 35
5.1 表面聲波晶片設計與製造 35
5.1.1 表面聲波晶片設計 35
5.1.2 表面聲波晶片製程 37
5.2 震盪電路設計 43
5.3 表面聲波感測晶片中心頻率量測 44
5.4 塗佈薄膜 46
5.4.1塗佈薄膜之選擇 46
5.4.2薄膜塗佈方式 47
5.5 表面聲波氣體感測晶片感測機制 48
5.5.1 頻率飄移效應 48
6.實驗系統架設與參數設計 51
6.1 熱脫附氣相層析質譜儀(TD – GC – MS) 51
6.1.1 樣品採集 52
6.1.2 儀器參數設定 54
6.1.3 結果分析方法 54
6.2 表面聲波氣體感測器量測系統 56
6.2.1 實驗所需儀器 56
6.2.2 實驗環境架設 61
6.2.3 實驗步驟 61
7. 表面聲波氣體感測器實驗結果與討論 66
7.1表面聲波氣體感測器對茶葉單一標準溶液分析 66
7.1.1 Linalool之量測 68
7.1.2 Hexenal之量測 70
7.1.3 Methyl salicylate之量測 72
7.1.4 Geraniol之量測 74
7.1.5 D-Limonene、Ocimene、Nonanal、Decanal、Benzaldehyde之量測 77
7.1.6 兩種感測薄膜對九種重要茶葉化合物之靈敏性 79
7.2表面聲波氣體感測器對茶葉六點位分析 80
7.2.1葡萄糖(Glucose)為感測薄膜對茶葉六點位之量測分析 81
7.2.2環糊精(B-CD)為感測薄膜對茶葉六點位之量測分析 85
7.3表面聲波氣體感測器對茶葉混合標準溶液分析 92
7.3.1 methyl salicylate與benzaldehyde之混合標準溶液 93
7.3.2 methyl salicylate與nonanal之混合標準溶液 95
7.3.3 methyl salicylate與decanal之混合標準溶液 97
8.結論與未來規劃 100
8.1結論 100
8.2未來規劃 102
參考文獻 104

[1] J. Tan and J. Xu, "Applications of electronic nose (e-nose) and electronic tongue (e-tongue) in food quality-related properties determination: A review," Artificial Intelligence in Agriculture, vol. 4, pp. 104-115, 2020.
[2] A. D. Wilson, "Future applications of electronic-nose technologies in healthcare and biomedicine," In: Akyar, Isin, ed. 2011. Wide Spectra of Quality Control. InTech Publishing, Rijeka, Croatia. 267-290., pp. 267-290, 2011.
[3] B. Szulczyński et al., "Different ways to apply a measurement instrument of E-nose type to evaluate ambient air quality with respect to odour nuisance in a vicinity of municipal processing plants," Sensors, vol. 17, no. 11, p. 2671, 2017.
[4] A. Shahid, J.-H. Choi, A. U. H. S. Rana, and H.-S. Kim, "Least squares neural network-based wireless E-Nose system using an SnO2 sensor array," Sensors, vol. 18, no. 5, p. 1446, 2018.
[5] X. Zhang, J. Cheng, L. Wu, Y. Mei, N. Jaffrezic-Renault, and Z. Guo, "An overview of an artificial nose system," Talanta, vol. 184, pp. 93-102, 2018.
[6] J. Gebicki, "Application of electrochemical sensors and sensor matrixes for measurement of odorous chemical compounds," TrAC Trends in Analytical Chemistry, vol. 77, pp. 1-13, 2016.
[7] H. T. Nagle, R. Gutierrez-Osuna, and S. S. Schiffman, "The how and why of electronic noses," IEEE spectrum, vol. 35, no. 9, pp. 22-31, 1998.
[8] L. Spinelle, M. Gerboles, G. Kok, S. Persijn, and T. Sauerwald, "Review of portable and low-cost sensors for the ambient air monitoring of benzene and other volatile organic compounds," Sensors, vol. 17, no. 7, p. 1520, 2017.
[9] B. Szulczyński and J. Gębicki, "Currently commercially available chemical sensors employed for detection of volatile organic compounds in outdoor and indoor air," Environments, vol. 4, no. 1, p. 21, 2017.
[10] K. Länge, B. E. Rapp, and M. Rapp, "Surface acoustic wave biosensors: a review," Analytical and bioanalytical chemistry, vol. 391, no. 5, pp. 1509-1519, 2008.
[11] S.-Y. Lin, L.-C. Lo, I.-Z. Chen, and P.-A. Chen, "Effect of shaking process on correlations between catechins and volatiles in oolong tea," journal of food and drug analysis, vol. 24, no. 3, pp. 500-507, 2016.
[12] A. Voss et al., "Detecting cannabis use on the human skin surface via an electronic nose system," Sensors, vol. 14, no. 7, pp. 13256-13272, 2014.
[13] A. D. Wilson, "Review of electronic-nose technologies and algorithms to detect hazardous chemicals in the environment," Procedia Technology, vol. 1, pp. 453-463, 2012.
[14] S. Y. Park, Y. Kim, T. Kim, T. H. Eom, S. Y. Kim, and H. W. Jang, "Chemoresistive materials for electronic nose: Progress, perspectives, and challenges," InfoMat, vol. 1, no. 3, pp. 289-316, 2019.
[15] G. Ouyang and J. Pawliszyn, "A critical review in calibration methods for solid-phase microextraction," Analytica chimica acta, vol. 627, no. 2, pp. 184-197, 2008.
[16] E. Omanovic-Miklicanin, S. Valzacchi, C. Simoneau, D. Gilliland, and F. Rossi, "Solid-phase microextraction/gas chromatography–mass spectrometry method optimization for characterization of surface adsorption forces of nanoparticles," Analytical and bioanalytical chemistry, vol. 406, no. 26, pp. 6629-6636, 2014.
[17] C. Rodríguez-Navas, R. Forteza, and V. Cerdà, "Use of thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) on identification of odorant emission focus by volatile organic compounds characterisation," Chemosphere, vol. 89, no. 11, pp. 1426-1436, 2012.
[18] F. Tateo and M. Bononi, "Determination of gamma-butyrolactone (GBL) in foods by SBSE-TD/GC/MS," Journal of food composition and analysis, vol. 16, no. 6, pp. 721-727, 2003.
[19] B. Patrizi, M. Siciliani de Cumis, S. Viciani, and F. D’Amato, "Dioxin and related compound detection: Perspectives for optical monitoring," International journal of molecular sciences, vol. 20, no. 11, p. 2671, 2019.
[20] M. Jackson and H. H. Mantsch, "The use and misuse of FTIR spectroscopy in the determination of protein structure," Critical reviews in biochemistry and molecular biology, vol. 30, no. 2, pp. 95-120, 1995.
[21] T. J. Christian et al., "Comprehensive laboratory measurements of biomass‐burning emissions: 1. Emissions from Indonesian, African, and other fuels," Journal of Geophysical Research: Atmospheres, vol. 108, no. D23, 2003.
[22] J. Cai, P. Lin, X. Zhu, and Q. Su, "Comparative analysis of clary sage (S. sclarea L.) oil volatiles by GC–FTIR and GC–MS," Food chemistry, vol. 99, no. 2, pp. 401-407, 2006.
[23] B. C. Smith, Fundamentals of Fourier transform infrared spectroscopy. CRC press, 2011.
[24] J. Kim, "Development and experimental analysis of a micro-flame ionization detector for portable gas chromatographs," University of Illinois at Urbana-Champaign, 2014.
[25] S.-T. Ho, J.-J. Wang, W.-J. Liaw, C.-M. Ho, and J.-H. Li, "Determination of tramadol by capillary gas chromatography with flame ionization detection: Application to human and rabbit pharmacokinetic studies," Journal of Chromatography B: Biomedical Sciences and Applications, vol. 736, no. 1-2, pp. 89-96, 1999.
[26] J. K. Volkman and P. D. Nichols, "Applications of thin layer chromatography-flame ionization detection to the analysis of lipids and pollutants in marine and environmental samples," JPC Journal of planar chromatography-Modern TLC, vol. 4, no. 1, pp. 19-26, 1991.
[27] S. Z. Hussain and K. Maqbool, "GC-MS: Principle, Technique and its application in Food Science," International Journal of Current Science, vol. 13, pp. 116-126, 2014.
[28] J. Tian et al., "Phenotype differentiation of three E. coli strains by GC-FID and GC–MS based metabolomics," Journal of Chromatography B, vol. 871, no. 2, pp. 220-226, 2008.
[29] H. Niemann et al., "The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe," Nature, vol. 438, no. 7069, pp. 779-784, 2005.
[30] M. Ryhl-Svendsen and J. Glastrup, "Acetic acid and formic acid concentrations in the museum environment measured by SPME-GC/MS," Atmospheric Environment, vol. 36, no. 24, pp. 3909-3916, 2002.
[31] H. Ono et al., "Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods," Food Additives & Contaminants, vol. 20, no. 3, pp. 215-220, 2003.
[32] J. E. Amoore, "Evidence for the chemical olfactory code in man," Annals of the New York Academy of Sciences, vol. 237, no. 1, pp. 137-143, 1974.
[33] K. R. Krishna, Aerial Robotics in Agriculture: Parafoils, Blimps, Aerostats, and Kites. Apple Academic Press, 2021.
[34] H. Nazemi, A. Joseph, J. Park, and A. Emadi, "Advanced micro-and nano-gas sensor technology: A review," Sensors, vol. 19, no. 6, p. 1285, 2019.
[35] A. Dey, "Semiconductor metal oxide gas sensors: A review," Materials Science and Engineering: B, vol. 229, pp. 206-217, 2018.
[36] S. R. Prasad, "“Synthesis and Characterization of ZnO and SiO2 Nanoparticles Doped Polypyrrole for Gas Sensing Application” Thesis," Central Scientific Instruments Organisation.
[37] S. Buratti et al., "Monitoring of alcoholic fermentation using near infrared and mid infrared spectroscopies combined with electronic nose and electronic tongue," Analytica chimica acta, vol. 697, no. 1-2, pp. 67-74, 2011.
[38] S. I. Boyadjiev and M. M. Rassovska, "WO3 THIN FILMS DEPOSITION ON QUARTZ CRYSTAL RESONATORS FOR APPLICATIONS IN GAS SENSORS," 2007.
[39] C. O’sullivan and G. Guilbault, "Commercial quartz crystal microbalances–theory and applications," Biosensors and bioelectronics, vol. 14, no. 8-9, pp. 663-670, 1999.
[40] W. P. Jakubik, "Surface acoustic wave-based gas sensors," Thin Solid Films, vol. 520, no. 3, pp. 986-993, 2011.
[41] P. Sharma et al., "Monitoring the fermentation process of black tea using QCM sensor based electronic nose," Sensors and Actuators B: Chemical, vol. 219, pp. 146-157, 2015.
[42] L. Rayleigh, "On waves propagated along the plane surface of an elastic solid," Proceedings of the London mathematical Society, vol. 1, no. 1, pp. 4-11, 1885.
[43] M. L. Smith and F. Dahlen, "The azimuthal dependence of Love and Rayleigh wave propagation in a slightly anisotropic medium," Journal of Geophysical Research, vol. 78, no. 17, pp. 3321-3333, 1973.
[44] R. M. White and F. W. Voltmer, "Direct piezoelectric coupling to surface elastic waves," Applied physics letters, vol. 7, no. 12, pp. 314-316, 1965.
[45] J. J. Campbell and W. R. Jones, "A method for estimating optimal crystal cuts and propagation directions for excitation of piezoelectric surface waves," IEEE Transactions on Sonics and Ultrasonics, vol. 15, no. 4, pp. 209-217, 1968.
[46] H. Wohltjen and R. Dessy, "Surface acoustic wave probe for chemical analysis. I. Introduction and instrument description," Analytical chemistry, vol. 51, no. 9, pp. 1458-1464, 1979.
[47] W. Wang, S. He, S. Li, and Y. Pan, "High frequency stability oscillator for surface acoustic wave-based gas sensor," Smart materials and structures, vol. 15, no. 6, p. 1525, 2006.
[48] W. Wen, H. Shitang, L. Shunzhou, L. Minghua, and P. Yong, "Enhanced sensitivity of SAW gas sensor coated molecularly imprinted polymer incorporating high frequency stability oscillator," Sensors and Actuators B: Chemical, vol. 125, no. 2, pp. 422-427, 2007.
[49] P. Panda and B. Sahoo, "PZT to lead free piezo ceramics: a review," Ferroelectrics, vol. 474, no. 1, pp. 128-143, 2015.
[50] H. A. Sodano, D. J. Inman, and G. Park, "A review of power harvesting from vibration using piezoelectric materials," Shock and Vibration Digest, vol. 36, no. 3, pp. 197-206, 2004.
[51] J. Kirschner, "Surface acoustic wave sensors (SAWS)," Micromechanical Syst, vol. 6, pp. 1-11, 2010.
[52] H. Ohigashi, "Electromechanical properties of polarized polyvinylidene fluoride films as studied by the piezoelectric resonance method," Journal of Applied Physics, vol. 47, no. 3, pp. 949-955, 1976.
[53] K. Uchino, Advanced piezoelectric materials: Science and technology. Woodhead Publishing, 2017.
[54] W. H. Grover, "Interdigitated array electrode sensors: their design, efficiency, and applications," 1999.
[55] Y. Ai, C. K. Sanders, and B. L. Marrone, "Separation of Escherichia coli bacteria from peripheral blood mononuclear cells using standing surface acoustic waves," Analytical chemistry, vol. 85, no. 19, pp. 9126-9134, 2013.
[56] D. Roshchupkin, T. Fournier, M. Brunel, O. Plotitsyna, and N. Sorokin, "Scanning electron microscopy observation of excitation of the surface acoustic waves by the regular domain structures in the LiNbO3 crystals," Applied physics letters, vol. 60, no. 19, pp. 2330-2331, 1992.
[57] G. G. Yaralioglu, A. S. Ergun, B. Bayram, E. Haeggstrom, and B. T. Khuri-Yakub, "Calculation and measurement of electromechanical coupling coefficient of capacitive micromachined ultrasonic transducers," IEEE transactions on ultrasonics, ferroelectrics, and frequency control, vol. 50, no. 4, pp. 449-456, 2003.
[58] G. Bu, D. Ciplys, M. Shur, L. Schowalter, S. Schujman, and R. Gaska, "Electromechanical coupling coefficient for surface acoustic waves in single-crystal bulk aluminum nitride," Applied physics letters, vol. 84, no. 23, pp. 4611-4613, 2004.
[59] J. G. Gualtieri, J. A. Kosinski, and A. Ballato, "Piezoelectric materials for acoustic wave applications," IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 41, no. 1, pp. 53-59, 1994.
[60] G. Bu, D. Ciplys, M. Shur, L. Schowalter, S. Schujman, and R. Gaska, "Temperature coefficient of SAW frequency in single crystal bulk AlN," Electronics letters, vol. 39, no. 9, pp. 755-757, 2003.
[61] A. Feteira, "Negative temperature coefficient resistance (NTCR) ceramic thermistors: an industrial perspective," Journal of the American Ceramic Society, vol. 92, no. 5, pp. 967-983, 2009.
[62] M. Tomar, V. Gupta, and K. Sreenivas, "Temperature coefficient of elastic constants of SiO2 over-layer on LiNbO3 for a temperature stable SAW device," Journal of Physics D: Applied Physics, vol. 36, no. 15, p. 1773, 2003.
[63] C. S. Kim, K. Yamanouchi, S. Karasawa, and K. Shibayama, "Temperature dependence of the elastic surface wave velocity on LiNbO3 and LiTaO3," Japanese Journal of Applied Physics, vol. 13, no. 1, p. 24, 1974.
[64] T. Kodama, H. Kawabata, H. Sato, and Y. Yasuhara, "Design of low–loss saw filters employing distributed acoustic reflection transducers," Electronics and Communications in Japan (Part II: Electronics), vol. 70, no. 9, pp. 32-44, 1987.
[65] S. Jyomura, K. Nagatsuma, and H. Takeuchi, "SAW propagation loss mechanism in piezoelectric ceramics," Journal of Applied Physics, vol. 52, no. 7, pp. 4472-4478, 1981.
[66] R. F. Milsom, N. Reilly, and M. Redwood, "Analysis of generation and detection of surface and bulk acoustic waves by interdigital transducers," IEEE Transactions on Sonics Ultrasonics, vol. 24, pp. 147-166, 1977.
[67] J. K. Na, J. L. Blackshire, and S. Kuhr, "Design, fabrication, and characterization of single-element interdigital transducers for NDT applications," Sensors and Actuators A: Physical, vol. 148, no. 2, pp. 359-365, 2008.
[68] H. Wohltjen, "Mechanism of operation and design considerations for surface acoustic wave device vapour sensors," Sensors and Actuators, vol. 5, no. 4, pp. 307-325, 1984.
[69] K. Lakin, "Electrode resistance effects in interdigital transducers," IEEE Transactions on Microwave Theory and Techniques, vol. 22, no. 4, pp. 418-424, 1974.
[70] W. R. Smith, H. M. Gerard, J. H. Collins, T. M. Reeder, and H. J. Shaw, "Design of surface wave delay lines with interdigital transducers," IEEE Transactions on Microwave Theory and Techniques, vol. 17, no. 11, pp. 865-873, 1969.
[71] T.-S. Tseng, M.-H. Hsiao, P.-A. Chen, S.-Y. Lin, S.-W. Chiu, and D.-J. Yao, "Utilization of a Gas-Sensing System to Discriminate Smell and to Monitor Fermentation during the Manufacture of Oolong Tea Leaves," Micromachines, vol. 12, no. 1, p. 93, 2021.
[72] P. Sharma et al., "Detection of linalool in black tea using a quartz crystal microbalance sensor," Sensors and Actuators B: Chemical, vol. 190, pp. 318-325, 2014.