本研究先以低溫共燒陶瓷製作平板型擴流器微泵主體，再用蓋玻片作為微泵之震動板與觀景窗，在致動器方面，我們選用性質穩定的PZT-5A。接著使用微粒子成像測速系統對微泵之暫態流場進行影像擷取及分析，但由於目前所使用的雷射光源強度不足，而且又有螢光粒子聚積在流道壁面上，所以無法透過相關性比對得到完整的速度場。因此我們將微粒子成像測速系統作為流場之可視性化工具。觀測結果發現，在致動頻率為200 Hz 時，出現不同於其它作動頻率造成的流場現象；當頻率範圍落在20 至150 Hz，粒子振動軌跡均是隨頻率上升而逐漸縮短，但在200 Hz 時，粒子振動軌跡不但增長，而且流場出現明顯的渦流，實驗結果顯示，在此頻率下微泵的淨流量亦接近最大值。

In this study, we use low-temperature co-fire ceramic to fabricate the main part of a planer-diffuser-type valveless micropump. The pump cavity and the flow channels are sealed by glass wafers, working as the actuation diaphragm and viewing window. A PZT-5A piezoelectric disc is glued on the diaphragm to drive the pump. We try to analyze the transient flow field in the channel using a micro particle image velocimetry. However, due to the deficiency of the laser intensity and the aggregation of dyed particles on the walls, the velocity fields built from the PIV images are incomplete. The micro-PIV system is then applied to visualize the flow qualitatively. Results from the observation show that the characteristics of the flow field at the actuation frequency of 200 Hz are very different from other driving frequencies. For frequency between 20 and 150 Hz, the length of the track of the oscillating particle decreases with increasing frequency. At 200 Hz, the track length increases considerably and severe vortexes are observed close to the diffuser neck. Interestingly, at this frequency, the pump exhibits an optimal net flow rate.

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