微反應器(Microreactor)是一種具有微小流體通道的化學反應設備，具備高表面積體積比、熱質傳輸效率高、反應控制精準及安全性佳等優勢。已廣泛應用於化學品高通量生產、藥物篩選、便攜式設備開發及反應機制研究等領域。因此微反應器在學術界和化學、製藥等產業中皆受到高度關注與積極研究。
在航太領域中，(Hydroxylammonium nitrate, HAN)作為一種新型綠色太空推進劑，具有比傳統液態推進劑聯胺(Hydrazine)更高的比衝、更低的毒性以及更佳的儲存穩定性，因此成為未來太空推進劑的重要候選材料。HAN多以水溶液形式存在，其製備過程涉及酸鹼中和反應，屬於強烈放熱反應，並且其產物對溫度敏感，需在低溫環境（低於 -4°C）中進行，以避免分解或降低穩定性。因此如何在安全、穩定且高效的條件下合成HAN水溶液，是其實際應用前的重要研究課題。
本研究針對HAN水溶液的合成問題，設計並製作一套連續式合成系統，運用自製之Y型混合器進行酸鹼中和反應，實現HAN水溶液的連續合成。此連續合成系統能維持反應條件於低溫區間，避免高溫所導致的產物降解。實驗中量測所得HAN水溶液的性質，包括密度、pH值，並以ATR-FTIR(Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy)光譜分析其官能基特徵，藉此確認產物組成與純度。同時將連續合成所得樣品與傳統批次滴定法所製備之HAN水溶液進行比較，驗證連續式合成系統的可行性與潛力。
為實現上述系統，本研究嘗試應用雷射箔材列印技術(Laser-Foil-Printing, LFP)製作微反應器。透過雷射選擇性熔融金屬箔材，逐層堆疊與燒結，實現具複雜流道結構的多層微流道結構。並針對製作過程中如層間對準精度、確保封閉性、雷射參數調整等挑戰，提出對應調整策略，確保微流道結構可穩定運作且具備良好機械性質與化學耐受性。也同時證明LFP技術在製作精密微結構裝置上的應用潛力。

Microreactors are chemical reaction devices featuring micro-scale fluidic channels, characterized by their high surface-area-to-volume ratio, efficient heat and mass transfer, precise reaction control, and enhanced operational safety. These advantages have led to their widespread application in high-throughput chemical synthesis, pharmaceutical screening, portable device development, and reaction mechanism studies. As a result, microreactors have attracted significant attention and active research in both academia and industries such as chemistry and pharmaceuticals.In the aerospace field, hydroxylammonium nitrate (HAN) has emerged as a promising green propellant, offering higher specific impulse, lower toxicity, and better storage stability compared to traditional liquid propellants such as hydrazine. HAN is typically prepared as an aqueous solution via a strongly exothermic acid-base neutralization reaction. However, the resulting solution is thermally sensitive and must be synthesized at low temperatures (below −4 °C) to prevent decomposition and maintain stability. Therefore, developing a safe, stable, and efficient method for HAN solution synthesis is a critical step toward its practical application.This study addresses the synthesis challenges of HAN aqueous solutions by designing and constructing a continuous-flow reaction system. A custom-designed Y-type micromixer was employed to perform the acid-base neutralization under controlled low-temperature conditions, enabling continuous HAN synthesis while minimizing thermal degradation. The synthesized HAN solutions were characterized by measuring physical properties such as density and pH, and further analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to identify functional groups and verify product composition and purity. The results were compared with those obtained from conventional batch titration methods, confirming the feasibility and potential of the continuous-flow approach.To implement this system, a multi-layer microreactor with complex internal flow channels was successfully fabricated using laser-foil-printing (LFP) technology. This additive manufacturing method involves selective laser melting and sintering of stacked metal foils to form integrated microfluidic structures. Key challenges such as interlayer alignment precision, sealing integrity, and laser parameter optimization were addressed through systematic adjustments. The resulting microreactors demonstrated stable operation, robust mechanical properties, and high chemical resistance. These findings also highlight the applicability of LFP in producing intricate microstructured devices for advanced chemical processing.

[1] E.D. Lavric and C. Cerato-Noyerie (2012), Mass Transfer in Gas-Liquid Flow in Corning Advanced-Flow Reactors, Chemical Engineering Transactions 29, 979-984.
[2] T.W. Phillips, I.G. Lignos, R.M. Maceiczyk, A.J. DeMello and J.C. DeMello (2014), Nanocrystal Synthesis in Microfluidic Reactors: Where Next?, Lab on a Chip 14, 3172-3180.
[3] J. Yoshida, Y. Takahashi and A. Nagaki (2013), Flash Chemistry: Flow Chemistry that Cannot Be Done in Batch, Chemical Communications 49, 9896-9904.
[4] F. Zhang, C.C. Noyerie, P. Woehl and D. Lavric (2011), Intensified Liquid-Liquid Mass Transfer in Corning Advanced-Flow Reactors, Chemical Engineering Transactions 24, 1369-1374.
[5] L. Capretto, D. Carugo, S. Mazzitelli, C. Nastruzzi and X. Zhang (2013), Microfluidic and Lab-on-a-Chip Preparation Routes for Organic Nanoparticles and Vesicular Systems for Nanomedicine Applications, Advanced Drug Delivery Reviews 65, 1496-1532.
[6] F. Fanelli, G. Parisi, L. Degennaro and R. Luisi (2017), Contribution of Microreactor Technology and Flow Chemistry to the Development of Green and Sustainable Synthesis, Beilstein Journal of Organic Chemistry 13, 520-542.
[7] D.E. Fitzpatrick and S.V. Ley (2018), Engineering Chemistry for the Future of Chemical Synthesis, Tetrahedron 74, 3084-3100.
[8] D. Liu, S. Cito, Y. Zhang, C. Wang, T.M. Sikanen and H.A. Santos (2015), A Versatile and Robust Microfluidic Platform Toward High Throughput Synthesis of Homogeneous Nanoparticles with Tunable Properties, Advanced Materials 27, 2298-2304.
[9] C.S. Martínez-cisneros, S.G. Pedro, M. Puyol, J. García-garcíaa and J. Alonso-chamarro (2012), Design Fabrication and Characterization of Microreactors for High Temperature Synthesis, Chemical Engineering Journal 211, 432-441.
[10] J. Wegner, S. Ceylan and A. Kirschning (2012), Flow Chemistry – A Key Enabling Technology for (Multistep) Organic Synthesis, Advanced Synthesis & Catalysis 354, 17-57.
[11] Z.V. Feng, K.R. Edelman and B.P. Swanson (2015), Student-Fabricated Micro Fluidic Devices as Flow Reactors for Organic and Inorganic Synthesis, Journal of Chemical Education 92, 723-727.
[12] R. Porta, M. Benaglia and A. Puglisi (2016), Flow Chemistry : Recent Developments in the Synthesis of Pharmaceutical Products, Organic Process Research & Development 20, 2-25.
[13] D.E. Fitzpatrick and S.V. Ley (2016), Engineering Chemistry: Integrating Batch and Flow Reactions on a Single, Automated Reactor Platform, Reaction Chemistry & Engineering 1, 629-635.
[14] K.F. Jensen, B.J. Reizman and S.G. Newman (2014), Tools for Chemical Synthesis in Microsystems, Lab on a Chip 14, 3206-3212.
[15] H. Uramachi, D. Shiraiwa, T. Takai, N. Tanaka, T. Kaneko and K. Furukawa (2019), Green Propulsion Systems for Satellites - Development of Thrusters and Propulsion Systems using Low-toxicity Propellants, Mitsubishi Heavy Industries Technical Review 56(1), 1-7.
[16] K. Hori, T. Katsumi, S. Sawai, N. Azuma, K. Hatai and J. Nakatsuka (2019), HAN‐Based Green Propellant, SHP163 – Its R&D and Test in Space, Propellants, Explosives, Pyrotechnics 44(9), 1080-1083.
[17] S. Hoyani, P. Patel, C. Oommen and R. Rajeev (2017), Thermal Stability of Hydroxylammonium Nitrate (HAN), Journal of Thermal Analysis and Calorimetry 129(2), 1083-1093.
[18] K.I. Lao, Catalytic Decomposition of HAN-Based Monopropellants with Hexaaluminates, Master Thesis, National Cheng Kung University, Taiwan, 2022.
[19] I.Y. Tsai, Reaction Characteristics of Hydroxylammonium Nitrate Based Propellants and the Development of Prototype Microthrusters, Master Thesis, National Cheng Kung University, Taiwan, 2023.
[20] J. Zhang, S. Yan, D. Yuan, G. Alici, N.T. Nguyen, M.E. Warkianic and W. Li (2016), Fundamentals and Applications of Inertial Microfluidics: A Review, Lab on a Chip 16, 10-34.
[21] K. Ward and Z.H. Fan (2015), Mixing in Microfluidic Devices and Enhancement Methods, HHS Public Access, PMC4634658.
[22] S. Mashaghi, A. Abbaspourrad, D.A. Weitz and A.M.V. Oijen (2016), Droplet Microfluidics: A Tool for Biology, Chemistry and Nanotechnology, Trends in Analytical Chemistry 82, 118-125.
[23] L. Rogers and K.F. Jensen (2019), Continuous Manufacturing – the Green Chemistry Promise?, Green Chemistry 21, 3481-3498.
[24] M. Movsisyan, E.I.P. Delbeke, J.K.E.T. Berton, C. Battilocchio, S.V. Ley and C.V. Stevens (2016), Taming Hazardous Chemistry by Continuous Flow Technology, Chemical Society Reviews 45, 4892-4928.
[25] R. Porta, M. Benaglia and A. Puglisi (2015), Flow Chemistry: Recent Developments in the Synthesis of Pharmaceutical Products, Organic Process Research & Development 20(1), 2-25.
[26] H. Zhang, J. Yang, R. Sun, S. Han, Z. Yang and L. Teng (2023), Microfluidics for Nano-Drug Delivery Systems: From Fundamentals to Industrialization, Acta Pharmaceutica Sinica B 13(8), 3277-3299.
[27] D. Kopetzki, F. Lévesque and P.H. Seeberger (2013), A Continuous-Flow Process for the Synthesis of Artemisinin, Chemistry – A European Journal 19(17), 5201-5494.
[28] P. Ruiz-Castillo and S.L. Buchwald (2016), Applications of Palladium-Catalyzed C–N Cross-Coupling Reactions, Chemical Reviews 116(19), 12564-12649.
[29] P.L. Suryawanshi, S.P. Gumfekar, B.A. Bhanvase, S.H. Sonawane and M.S. Pimplapure (2018), A Review on Microreactors: Reactor Fabrication, Design, and Cutting-Edge Applications, Chemical Engineering Science 189, 431-448.
[30] S. Aralekallu, R. Boddula and V. Singh (2023), Development of Glass-Based Microfluidic Devices: A Aeview on Its Fabrication and Biologic Applications, Materials & Design 225, 111517.
[31] A.G. Niculescu, C. Chircov, A.C. Bîrcă and A.M. Grumezescu (2021), Fabrication and Applications of Microfluidic Devices: A Review, International Journal of Molecular Sciences 22(4), 2011 PMC7921936.
[32] S.M. Scott and Z. Ali (2021), Fabrication Methods for Microfluidic Devices: An Overview, Micromachines 12(3), 319 PMC8002879.
[33] X.J. Yao, Y. Zhang, L.Y. Du, J.H. Liu and J.F. Yao (2015), Review of the Applications of Microreactors, Renewable and Sustainable Energy Reviews 47, 519-539.
[34] J. Hormes, J. Göttert, K. Lian, Y. Desta and L. Jian (2003), Materials for LiGA and LiGA-Based Microsystems, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 199, 332-341.
[35] C.S. Effenhauser, G.J.M. Bruin, A. Paulus and M. Ehrat (1997), Integrated Capillary Electrophoresis on Flexible Silicone Microdevices: Analysis of DNA Restriction Fragments and Detection of Single DNA Molecules on Microchips, Analytical Chemistry 69(17), 3451-3457.
[36] S. Cheemalapati, M. Ladanov, J. Winskas and A. Pyayt (2014), Optimization of Dry Etching Parameters for Fabrication of Polysilicon Waveguides with Smooth Sidewall Using a Capacitively Coupled Plasma Reactor, Applied Optics 53(25), 5745-5749.
[37] A. Hierlemann and H. Baltes (2003), CMOS-Based Chemical Microsensors, Analyst 128, 15-28.
[38] C.M. Huang and Y.C. Wang (2014), Design and Fabrication of a Valveless Micropump Based on Low Temperature Co-Fired Ceramic Tape Technology, Microsystem Technologies 20, 1111-1123.
[39] M.H. Wu and P.S. Lin (2010), Design, Fabrication and Characterization of a Low-Temperature Co-Fired Ceramic Gaseous Bi-Propellant Microthruster, Journal of Micromechanics and Microengineering 20(8), 085026.
[40] M.H. Wu and R.A. Yetter (2008), Development and Analysis of a LTCC Micro stagnation-Point Flow Combustor, Journal of Micromechanics and Microengineering 18(12), 125016.
[41] M.H. Wu and T.H. Lu (2012), Development of a Chemical Microthruster Based on Pulsed Detonation, Journal of Micromechanics and Microengineering 22(10), 105040.
[42] C.M. Huang, Y.C. Wang and M.H. Wu (2013), Development of a Fully Integrated Micro-Scale Fuel Reformer Over Platinum (Pt) Catalyst Based on Low Temperature Co-Fired Ceramic (LTCC) Tape Technology, Journal of the Chinese Society of Mechanical Engineers 34(3), 205-211.
[43] C. Chen, Y. Shen and H.L. Tsai (2017), A Foil-Based Additive Manufacturing Technology for Metal Parts, Journal of Manufacturing Science and Engineering 139(2), 024501.
[44] T.D. Ngo, A. Kashani, G. Imbalzano, K.T.Q. Nguyen and D. Hui (2018), Additive Manufacturing (3D Printing): A Review of Materials, Methods, Applications and Challenges, Composites Part B: Engineering 143, 172-196.
[45] D. Herzog, V. Seyda, E. Wycisk and C. Emmelmann (2016), Additive Manufacturing of Metals, Acta Materialia 117, 371-392.
[46] S. Cooke, K. Ahmadi, S. Willerth and R. Herring (2020), Metal Additive Manufacturing: Technology, Metallurgy and Modelling, Journal of Manufacturing Processes 57, 978-1003.
[47] X.B. Gong, T. Anderson and K. Chou (2014), Review on Powder-Based Electron Beam Additive Manufacturing Technology, Manufacturing Review 1, 2.
[48] Z.J. Sun, X.P. Tan, S.B. Tor and W.Y. Yeong (2016), Selective Laser Melting of Stainless Steel 316L with Low Porosity and High Build Rates, Materials & Design 104, 197-204.
[49] I. Tolosa, F. Garciandía, F. Zubiri, F. Zapirain and A. Esnaol (2010), Study of Mechanical Properties of AISI 316 Stainless Steel Processed by “Selective Laser Melting”, Following Different Manufacturing Strategies, International Journal of Advanced Manufacturing Technology 51, 639-647.
[50] Rightek technologies: https://www.rightek.com.tw/product_list/傅立葉轉換紅外線光譜儀-ftir
[51] H. OuYang, Synthesis Atmospheric Electrolytic Decomposition Characteristics of Hydroxylammonia Nitrate Aqueous Solutions, Master Thesis, National Cheng Kung University, Taiwan, 2020.
[52] D. Setiorini S, TG-FTIR Study on Pyrolysis and Oxy-combustion Characteristics of Rice Straw and Husk, Master Thesis, National Cheng Kung University, Taiwan, 2015.
[53] Y.X. Wang, Fabrication and Research of Crack-Free 6061 Aluminum Alloy Parts Using Laser Foil Printing Additive Manufacturing Processes, Master Thesis, National Cheng Kung University, Taiwan, 2024.
[54] C.H. Hung, Y.Q. Li, A. Sutton, W.T. Chen, X.T. Gong, H. Pan, H.L. Tsai and M.C. Leu (2020), Aluminum Parts Fabricated by Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, and Mechanical Properties, Materials 13(2), 414.
[55] Y.Q. Li, Y.Y. Shen, M.C. Leu and H.L. Tsai (2018), Building Zr-Based Metallic Glass Part on Ti-6Al-4V Substrate by Laser-Foil-Printing Additive Manufacturing, Acta Materialia 144, 810-821.
[56] T. Turk, M. Dougan, L. Hendrix, A. Reed, C.E. Dominguez, A.T. Sutton, J. Park and M.C. Leu (2023), Embedding Temperature Sensors with the Use of Laser-foil-printing Additive Manufacturing, Proceedings of the 34th Annual International Solid Freeform Fabrication Symposium (2023, Austin, TX), 124344.
[57] C.H. Hung, A. Sutton, Y.Q. Li, Y.Y. Shen, H.L Tsai and M.C. Leu (2019), Enhanced Mechanical Properties for 304L Stainless Steel Parts Fabricated by Laser-Foil-Printing Additive Manufacturing, Journal of Manufacturing Processes 45, 438-446.
[58] C.H. Hung, Y.Y. Shen, M.C. Leu and H.L. Tsai (2017), Mechanical Properties of 304L Parts Made by Laser-Foil-Printing Technology, Proceedings of the 28th Annual International Solid Freeform Fabrication Symposium (2017, Austin, TX), 1833-1845.