本研究主要設計一項二維無實體腔室微液珠產生器，利用精確的延遲加熱控制產生動態氣泡陣列，以形成一虛擬墨水腔室；液珠之噴發是藉由目標噴孔周圍特定排列的數個動態氣泡來規範噴發之壓力源，因此可以取代傳統噴頭所採用的實體分隔式墨水腔體。此二維無實體腔室微液珠產生器於定義完加熱器結構後，利用SU-8乾膜光阻在加熱器上方形成噴孔片結構，在加熱器之間並無任何實體腔體結構存在。由於省略實體腔室所佔據之晶片面積，因此本研究設計之二維噴孔密度可達到商用噴頭的五至十倍。經實驗測試，本設計所能產生之液珠體積與初始噴發速度分別為3.6-5.7 pL與14-15 m/s，皆能符合商用噴頭之標準。此外，由於精確的液面控制能力，此微液珠產生器於噴發時並未發現有衛星液滴之問題；由液珠移動距離之數據顯示，噴孔處之液面呈現一『推-拉-推』的過程，這是能有效剪斷噴射出之液柱而避免衛星液珠產生之關鍵。在墨水回填時間之估算方面，此微液珠產生器因無實體腔室，故流阻較小，回填時間估計僅需0.296 μs，約為商用噴頭所需時間之十分之ㄧ；再將液面震盪所需消耗之時間考慮進去，本設計所能達成之操作頻率估計約為20 kHz。最後我們呈現一3 x 5加熱器陣列，用來同時噴發兩顆液珠；由實驗結果可知，噴孔間的互擾問題可藉由精確的時序控制來予以避免。我們也提出了一交錯噴發的操作模式來說明此設計應用於大型陣列時的控制機制。
至於在微液珠產生器內的氣泡動態研究，本論文對於三顆氣泡於延遲加熱控制下因不同加熱起始時間、不同加熱器間距、不同順序加熱模式之相互影響有詳細的探討，目標是達成特定氣泡的能量集中與能量串級效應。在一特定的延遲加熱時間下，目標氣泡受到周圍氣泡輔助，使其最大氣泡體積可達單氣泡最大體積的二至三倍；此結果克服了傳統爆炸性沸騰在固定熱通量下能量利用率之限制。當加熱器間距縮小時，由於更強烈的流體動力影響與壓力波影響，目標氣泡會受到更明顯的『增進』或『抑制』效應。此外，在實驗中觀測到許多有趣的非球形氣泡動態，如：氣泡偏移、蕈狀氣泡、柱狀氣泡、或氣泡延伸至周圍加熱器上…等情形。本研究更進一步對三顆熱氣泡採用二階順序放大程序，以提供各種不同的氣泡體積組合，此結果可應用於需要多階可調式之微流體傳輸需求，亦可提供噴墨頭、微型幫浦之設計與操作參考。

[1] R. R. Allen, J. D. Meyer, and W. R. Knight, “Thermodynamics and hydrodynamics of thermal ink jets,” Hewlett-Packard Journal, vol. 36, pp. 21-27, 1985.
[2] J. P. Baker, D. A. Johnson, V. Joshi, and S. J. Nigro, “Design and development of a color thermal inkjet print cartridge,” Hewlett-Packard Journal, vol. 39, pp. 6-15, 1988.
[3] H. S. Koo, M. Chen, P. C. Pan, L. T. Chou, F. M. Wu, S. J. Chang, and T. Kawai, “Fabrication and chromatic characteristics of the greenish LCD colour-filter layer with nano-particle ink using inkjet printing technique,” Displays, vol. 27 pp. 124-129, 2006.
[4] H. S. Koo, M. Chen, and P. C. Pan, “LCD-based color filter fabricated by a pigment-based colorant photo resist inks and printing technology,” Thin Solid Films, vol. 515, pp.896-901, 2006.
[5] K. C. Fan, J. Y. Chen, C. H. Wang, and W. C. Pan, “Development of a drop-on-demand droplet generator for one-drop-fill technology,” Sens. Actuator A-Phys., Vol. 147, pp. 649–655, 2008.
[6] H. P. Cheng, and C. P. Chien, “Ejection characteristics of micropumps for motorcycle fuel atomizer in high-temperature environment,” Appl. Therm. Eng., vol. 28, pp. 94-109, 2008.
[7] L. Lonini, D. Accoto, S. Petroni, and E. Guglielmelli, “Dispensing an enzyme-conjugated solution into an ELISA plate by adapting ink-jet printers,” J. Biochem. Biophys. Methods, vol. 70, pp. 1180-1184, 2008.
[8] R. E. Saunders, J. E. Gough, and B. Derby, “Delivery of human fibroblast cells by piezoelectric drop-on-demand inkjet printing,” Biomaterials, vol. 29, pp. 193-203, 2008.
[9] M. Nakamura, Y. Nishiyama, C. Henmi, S. Iwanaga, H. Nakagawa, K. Yamaguchi, K. Akita, S. Mochizuki, and K. takiura, “Ink jet three-dimensional digital fabrication for biological tissue manufacturing analysis of alginate microgel beads produced by ink jet droplets for three dimensional tissue fabrication,” J. Imaging Sci. Technol., vol. 52, 060201, 2008.
[10] M. Nakamura, S. Iwanaga, C. Henmi, K. Akita, and Y. Nishiyama, “Biomatrices and biomaterials for future developments of bioprinting and biofabrication,” Biofabrication, vol. 2, 014110, 2010.
[11] F. G. Tseng, C. J. Kim, and C. M. Ho, “A high-resolution high-frequency monolithic top-shooting microinjector free of satellite drops—part i: concept, design, and model,” J. Microelectromech. Syst., vol. 11, no. 5, pp. 427-436, 2002.
[12] F. G. Tseng, C. J. Kim, and C. M. Ho, “A high-resolution high-frequency monolithic top-shooting microinjector free of satellite drops—part ii: fabrication, implementation, and characterization,” J. Microelectromech. Syst., vol. 11, no. 5, pp. 437-447, 2002.
[13] I. D. Yang, F. G. Tseng, C. M. Chang, and C. C. Chieng, “Microbubble formation dynamics under high heat flux on heaters with different aspect ratios,” Nanoscale Microscale Thermophys. Eng., vol. 10, pp. 1-28, 2005.
[14] I. D. Yang, T. F. Wu, C. Pan, F. G. Tseng, R. J. Yu, and C. C. Chieng, “Droplet ejection and the induced flowfield by micro thermal bubble during growth/collapse process,” Proc. IMechE vol. 220 Part C: J. Mechanical Engineering Science, pp. 1269-1281, 2006.
[15] I. D. Yang, F. G. Tseng, R. Y. Yu, and C. C. Chieng, “Bubble dynamics for explosive micro thermal dual bubbles,” J. Microelectromech. Syst., vol.16, no.3, pp. 734-745, 2007.
[16] C. M. Chang, I. D. Yang, Y. L. Lin, C. C. Chieng, and F. G. Tseng, “Efficient transfer and concentration of energy between explosive dual bubbles via time-delayed interactions,” Microfluid. Nanofluid., vol. 9 pp. 329-340, 2009.
[17] R. A. Askeland, W. D. Childers, and W. R. Sperry, “The second-generation thermal inkjet structure,” Hewlett-Packard Journal, vol. 39, no. 4, pp. 28-31, 1988.
[18] A. Asai, T. Hara, and I. Endo, “One-dimensional model of bubble growth and liquid flow in bubble jet printers.” Jpn. J. Appl. Phys., vol. 26, no. 10, pp. 1794-1801, 1987.
[19] P. H. Chen, W. C. Chen, and S. H. Chang, “Bubble growth and ink ejection process of a thermal ink jet printhead.” Int. J. Mech. Sci., vol. 39, no. 6, pp. 683-695, 1997.
[20] C. T. Avedisian, W. S. Osborne, F. D. McLeod, and C. M. Curley, “Measuring bubble nucleation temperature on the surface of a rapidly heated thermal ink-jet heater immersed in a pool of water,” Proc. R. Soc. Lond. A, vol. 455, pp 3875–3899, 1999.
[21] C. Rembe, S. aus der Wiesche, and E. P. Hofer, “Thermal ink jet dynamics: modeling, simulation, and testing,” Microelectron. Reliab., vol. 40, pp 525-532, 2000.
[22] Z. Zhao, S. Glod, and D. Poulikakos, “Pressure and power generation during explosive vaporization on a thin-film microheater,” Int. J. Heat Mass Transf., vol. 43, pp. 281–296, 2000.
[23] J. H. Lim, Y. S. Lee, H. T. Lim, S. S. Baek, K. Kuk, and Y. S. Oh, “Visualization of bubble generated by micro heaters with various current density distribution,” Proc. of the 16th IEEE MEMS, Jan 19-23, Kyoto, Japan, pp.197-200, 2003.
[24] Y. Hong, N. Ashgriz, and J. Andrews, “Experimental study of bubble dynamics on a micro heater induced by pulse heating,” ASME J. Heat Transfer, vol. 126, pp. 259-271, 2004.
[25] K. Okuyama, S. Tsukahara, N. Morita, and Y. Iida, “Transient behavior of boiling bubbles generated on the small heater of a thermal ink jet printhead,” Exp. Therm. Fluid Sci., vol. 28, pp. 825–834, 2004.
[26] S. Escobar-Vargas, D. Fabris, J. E. Gonzalez, R. Sharma, C. Bash, and O. E. Ruiz, “Bubble growth characterization during fast boiling in an enclosed geometry,” Int. J. Heat Mass Transf., vol. 52, pp. 5102-5112, 2009.
[27] Y. Tomita, A. Shima, and K. Sato, “Dynamic behavior of two-laser-induced bubbles in water,” Appl. Phys. Lett., vol. 57 pp. 234-236, 1990.
[28] L. Zhang, and M. Shoji, “Nucleation site interaction in pool boiling on the artificial surface,” Int. J. Heat Mass Transf., vol. 46, pp. 513-522, 2003.
[29] S. Chatpun, M. Watanabe, and M. Shoji, “Nucleation site interaction in pool nucleate boiling on a heated surface with triple artificial cavities,” Int. J. Heat Mass Transf., vol. 47, pp. 3583–3587, 2004.
[30] S. Chatpun, M. Watanabe, and M. Shoji, “Experimental study on characteristics of nucleate pool boiling by the effects of cavity arrangement,” Exp. Therm. Fluid Sci., vol. 29, pp. 33–40, 2004.
[31] N. Bremond, M. Arora, S. M. Dammer, and D. Lohse “Interaction of cavitation bubbles on a wall,” Phys. Fluids, vol. 18, 121505, 2006.
[32] N. Bremond, M. Arora, C. D. Ohl, and D. Lohse “Cavitation on surfaces,” J. Phys.: Condens. Matter, vol. 17, pp. 3603-3608, 2005.
[33] T. G. Kang, and Y. H. Cho, “A-four-bit digital microinjector using microheater array for adjusting the ejected droplet volume,” J. Microelectromech. Syst., vol. 14, no. 5, pp. 1031-1038, 2005.
[34] C. H. Je, T. G. Kang, and Y. H. Cho, “Droplet-volume-adjustable microinjectors using a digital combination of multiple current paths connected to single microheater,” J. Microelectromech. Syst., vol. 18, pp. 884-891, 2009.
[35] H. Dong, and W. W. Carr, “Visualization of drop-on-demand inkjet: drop formation and deposition,” Rev. Sci. Instrum., vol. 77, 085101, 2006.
[36] M. Einat, and N. Einat, “Two-dimensional full array high-speed ink-jet print head,” Appl. Phys. Lett., vol. 89, 073505, 2006.
[37] Y. Wang, and J. Bokor, “Ultra-high-resolution monolithic thermal bubble inkjet print head,” J. Micro/Nanolith. MEMS MOEMS, vol. 6, 043009, 2007.
[38] K. M. Vaeth, “Continuous inkjet drop generators fabricated from plastic substrates,” J. Microelectromech. Syst., vol. 16, pp. 1080-1086, 2007.
[39] R. Li, N. Ashgriz, and S. Chandra, “Droplet generation from pulsed micro-jets,” Exp. Therm. Fluid Sci., vol. 32, pp.1679-1686, 2008.
[40] Y. L. Lin, “The dynamic interactions of triple thermal bubbles with delayed heating pulse under high heat flux,” Master Thesis, National Tsing- Hua University, Taiwan, 2007.
[41] I. D. Yang, “The flow visualization of micro thermal bubble growth process and induced flow field,” Diss. National Hsing-Hua University, Taiwan, 2005.
[42] C. Weber, “Disintegration of liquid jets,” Z. angew. Math. Mech., vol.11, pp. 136-154, 1931.
[43] W. Ohnesorge, “Formation of drops by nozzles and the breakup of liquid jets,” Z. angew. Math. Mech., vol.16, pp. 355-358, 1936.
[44] M. Pilch, and C. A. Erdman, “Use of breakup time data and velocity history data to predict the maximum size of stable fragments for acceleration-induced breakup of a liquid-drop,” Int. J. Multiph. Flow, vol. 13, pp. 741-757, 1987.
[45] F. G. Tseng, “A micro droplet injector system,” Diss. University of California, Los Angeles, 1998.
[46] A. Olsson, G. Stenne, and E. Stemme, “A valve-less planar fluid pump with two pump chambers,” Sens. Actuator A-Phys., vol. 47, pp. 549-556, 1995.
[47] J. H. Tsai, and L. W. Lin, “A thermal-bubble-actuated micronozzle-diffuser pump,” J. Microelectromech. Sys., vol. 11, pp. 665-671, 2002.