系統剛性對無閥式微幫浦效能之影響及其應用

The system stiffness effect on the performance of valveless micropump and its applications

黃閔範(Min-Fan Huang)

指導教授 ： 王安邦

國立臺灣大學/工學院/應用力學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.11317

摘要

本研究探討系統剛性對無閥式微幫浦之影響，透過微幫浦周邊幾何尺寸之改變及外接材質的變更使其剛性產生差異，藉此觀察微幫浦特性與效能隨系統剛性之變化，再輔以電路類比法之模擬，證明各元件之剛性確實具有決定性之影響。
首先在第一部分，吾人發現微幫浦邊界的固定條件是一個影響性能的重要參數，由實驗顯示若比較無閥式微幫浦之進出口腔體有無被完全拘限住，未被完全拘限者的流量會比被完全侷限者高出兩倍之多。而當未被完全拘限微幫浦振動腔尺寸縮減一半時，依然能達到原尺寸完全拘限者淨流量時的大小。以尺寸縮減後的無閥式微幫浦進行在固定半徑比下不同角度變化之實驗，發現在不同角度下之共振頻淨流率量發展趨勢變化不大，表示角度改變應不是系統效能之主導因素。第二部分則以流量量測探討進出口幾何大小的改變所造成之影響，其結果發現進出口接管在使用較硬之管材(如:PP管)時，進出口對振動腔之半徑比(以下簡稱半徑比)為1.2時有最大流量(流量為14.9ml/min)；而若改變成較軟之管材(如:矽膠管)時，則在半徑比為1.8時有最大的流量(流量為15.6ml/min)。值得注意的是進行矽膠管實驗時，在200Hz左右的頻段會出現另一個共振頻，此結果代表外部接管元件之剛性也會明顯影響微幫浦之整體動態響應。第三部分為探討接管管材改變對腔體振動之影響，並透過雷射都普勒振動掃描儀量測壓電振動腔與進出口膜面之振動，以探討系統之動態特性反應。
最後，吾人利用微幫浦元件剛性變化所產生不同共振頻之特性，設計出一進口多出口之多通道無閥式微幫浦，以取代傳統上需多幫浦方可達成之多通道可控制功能，並透過流場顯影的方式驗證序列控制性能。由此應用證明吾人可透過單一幫浦以簡單調頻的方式操控流體方向，達到簡化設備需求並有效拓展無閥式微幫浦新應用範圍的目的。

關鍵字

無閥式微幫浦 ； 系統剛性 ； 旋轉角 ； 共振效應 ； 進出口共振腔體 ； 水力-電路類比模型

並列摘要

The influence of system stiffness on the performance of a valveless micropump was investigated in this research. The system stiffness of a valveless micropump was controlled by modifying the geometric dimension of micropump or altering the tubing material, and the corresponding effects on pumping performance were recorded and analyzed. With the aid of electronic-hydraulic analogy, it has been proven that the stiffness of connecting units can significantly influence the pumping efficiency.
First of all, the boundary condition of a micropump is discovered to be an important parameter which affects the pumping performance. With unconfined boundary, the flow rate of a micropump was twice higher than that with the fully confined boundary. Moreover, as the oscillating chamber size of the micropump was reduced to one-half, it can still reach the same flow rate as the original pump. For pumps with the same radius ratio but different rectifier angle, that the trends of flow rate and resonance frequencies are almost the same. This implies that the pumping angle should be not a dominant factor on pimping performance. Second, the effect of geometric of both inlet and outlet on pumping efficiency of a micropump were explored. The results showed that the maximum flow rate occurred as radius ratio equals 1.2 by using stiffer tubing material (polypropylene, PP). Once the tubing material was changed into softer one (silicon rubber, S.R.), the maximum flow rate occurred as radius ratio equals 1.8. It is worth noted that another resonance frequency showed up in the range around 200 Hz as the tubing material was S.R., which indicated that the stiffness of tubing would also affect the performace and dynamic response of a micropump. In the third part, the surface vibrations of oscillating chamber, inlet chamber, and outlet chamber of a micropump were measured by laser Doppler vibrometer. The system dynamic characteristics of a valveless micropump with different tubing materials was studied and analyzed.
At the end, the stiffness dependent characteristic of the resonance frequency was utilized to design a valveless micropump with one inlet and multiple outlets. This novel design can be applied to replace multiple pumps by using only a single pump for pumping control. Flow visualization was performed to demonstrate the sequential flow control of of multiple channel control system, by simply tuning the operation frequency. This new design can significantly extend the applicable range of valveless micropumps.

並列關鍵字

valveless micropump ； system stiffness ； rotating angle ； resonance frequncy ； geometry ratio ； electronic-hydraulic analogy

參考文獻

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