微轉子式微流體幫浦暨混合裝置

Abstract

在微流體的領域中，如何使兩種以上的流體快速的混合是很重要的議題；本論文利用微機電製程技術，成功的開發出一種本身具有推動流體且具混合能力的新型微流體裝置。其驅動流體及啟動微轉子混合機制的元件皆是透過無閥門壓電微幫浦，當貼附於微幫浦振動腔體的壓電片上下反覆振動，會使微流道內的流體產生往復運動進而推動微轉子混合區內的微轉子，另外透過改變對壓電片的操作訊號，可以改變微轉子的轉速，使欲混合流體受到不同程度的攪拌，藉著破壞流體之間存在的流體界面，可以使混合效能大大提升。本研究開發的微轉子幫浦混合裝置其尺寸大小為長25mm、寬11mm、厚0.65mm，並由實驗結果得知，此裝置能夠在操作電壓10Vpp~40Vpp、操作頻率0.1kHz~1.5kHz下，能驅動15~130ul/min的體積流率，且擁有在10Vpp的低操作電壓下，將混合指標提升至0.9的高混合能力。本文將說明微轉子混合機制的設計方法，同時建立完整的實驗方法，進一步證實了微轉子幫浦混合裝置的可行性，未來可將積體電路或其他元件整合於晶片上，成為低成本的微流體系統。

For microfluidic flows, one of the very important subjects is to have two or more fluids thoroughly mix in a short time and distance. In this study, a new microfluidic device possesses both pumping and mixing capabilities has been successfully developed by MEMS techniques. The flow was driven by a PZT valveless micropump and a microrotor was integrated into the pumping system. The oscillatory flow provided by the pumping chamber impinged the microrotor blades to have the microrotor rotate. The dimensions of the present micro-device are 25 mm in length, 11 mm in width, and 0.65 mm in thickness. The results revealed that mixing qualities were affected by rotating speeds of the microrotor, which depended on the driving frequencies and voltages. The mixing efficiencies were significantly enhanced by increasing the rotating speed which could rapidly stir the two different fluids and increase their interfacial areas. In this experiment, the flow rates of 15-130ul/min were measured at excitation voltages of 10-40 Vpp and frequency of 0.1k~1.5 kHz. Moreover, results show that good mixing efficiencies were demonstrated and the mixing indices were higher than 0.9. In summary, the current device with simple fabrication presents high pumping capability and mixing efficiencies even at low excitation voltages. These characteristics are all favorable for the integration in a microfluidic system.