本研究主要是運用微機電技術製作微加熱器(Micro Heater)於微噴嘴管道(Micro Nozzle Channel)內，比較微噴嘴管道內有無結構式閥門(Structural Valve)或虛擬熱泡式閥門(Virtual Thermal Buuble Valve)作用下，探討不同輸入功率下汽泡的動力行為，其中包括汽泡成長速率(Bubble growth rate)、汽泡交界面成長與微加熱器相對距離及汽泡與汽泡交互作用行為。
本研究以自行發展架設之微流體高速顯微影像觀測分析實驗系統，測試自製之微噴嘴管道致動器(Micro Nozzle Channel actuator)，觀察致動器內部受到結構式閥門或虛擬熱泡式閥門作用影響下熱汽泡動力之相關行為，並藉由實驗影片量測及分析汽泡成長大小及速率。
研究結果發現虛擬閥門機制可影響汽泡在微管道成長過程中產生不對稱性成長，迫使汽泡交界面往下游噴嘴方向較往上游儲存槽方向移動速率快，有效增加液體往噴嘴方向推進的速度。經由固定能量條件下汽泡成長速率實驗結果，本研究發現可定義一無因次時間參數(t*)，從無因次時間參數重新描述汽泡成長曲線發現，汽泡成長在不同脈衝訊號下有一致動力行為，汽泡成長曲線可由一逼近曲線取得一經驗公式去描述不同脈衝訊號下汽泡成長動力行為，此經驗公式發現汽泡成長速率隨著無因次化時間 變化成長，由影像觀測中汽泡成長速度快速，在各種閥門機制下汽泡大小均在t*>0.1時已大於管徑大小(50μm)，因此汽泡表面積與管壁大部分接觸，表面熱傳效應增強，因此在汽泡動力理論分析中由結果推論本研究之汽泡成長機制應屬熱傳/擴散主宰機制(heat transfer/diffusion control bubble growth)。

In this research, the dynamic behaviors of bubble are studied inside a micro-nozzle channel. Within the micro-nozzle channel, different valve designs are used, including conventional structural valve as well as virtual bubble valve. Different dynamics of the bubbles, for examples the bubble growth rate and bubble interface movement, under different input powers and various valve situations are measured using a high speed microscopic visualization system. The experimental results show that the virtual bubble valve causes the asymmetric bubble growth. With the help of virtual bubble valve, the bubble interface will kin to move downstream, instead of upstream which will enhance the driven force to the liquid toward the nozzle direction. In this study, a nondimensional timescale (t*) can be defind. By using this dimensionless timescale, one can collapse the bubble growth curves for different power input cases into one curve. The bubble growth rate is found to be proportional to t*1/2. A physical modeling is also proposed that indicates this bubble growth behavior of t*1/2 is a heat transfer (diffusion) control mechanism with large parts of bubble interface contact with upper and lower walls of micro nozzle channel.

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