本研究研發一創新之三維微流場量測技術-多光譜三維微粒循跡測速儀(Multi-Spectra 3-D ?-PTV)，利用三針孔多光譜濾鏡陣列與對焦的概念，達到三維三向量(3D-3C)之量測，並採用了三台單色攝影機擷取通過個別濾鏡之影像以增加影像訊雜比。利用校正實驗找出顯微鏡物鏡在微流道之對焦平面(Focus plane)，並將攝影機攝得之微粒影像進行影像後處理與疊加，可得三聯影像光點。分析其所構成的三角形大小可計算此微粒位於空間中的深度座標。本研究亦以微铣削技術(Micro-Milling)製造PDMS 微流道之母模，可節省製造成本。實驗結果成功製作凸塊及氣泡式微結構產生穩態射流(Steady-Streaming)之微流體裝置，結構特徵尺寸為0.2mm 與0.5mm。實驗結果比較不同尺寸與微結構產生穩態渦旋效應之差異，並藉由觀測所計算之微流場之不同視角的剖面圖中可以發現穩態渦旋的流動特性與影響範圍。兩種結構所產生的穩態渦旋以氣泡結構較有能力將振動能量傳給流體形成穩態渦旋，故能夠形成較強的渦旋效應並帶動周圍流體流動，並使得流場中無明顯微小渦流現象的產生。文中藉由分析穩態渦旋速度發現，不管何種結構所產生的渦旋其中心都具備著最快的速度值並由中心往外逐漸遞減，並以中心為圓心畫出穩態渦旋半徑即可界定出其影響的範圍。

A novel volumetric technique, the Multi-Spectra Three-Dimensional Micro-Particle Tracking Velocimetry (Multi-Spectra 3-D ?-PTV), is developed for measuring microscale three-dimensional, three-component (3D-3C) flows. Utilizing the concept of 3-pinhole multi-spectra filter array, the system can achieve higher SNR with three monochrome cameras. With proper calibration, the focal plane of the objective lens of the microscope can be found, and the particle images captured by the three monochrome cameras can be processed and superimposed to create the triplet images. The size of the triangular pattern can be analyzed to obtain the depth location of the particle in physical space. The casts of the microfluidic device are made by micro-milling process to reduce the manufacturing cost. Steady-streaming microfluidics devices with bubble or semi-cylindrical micro-structures of 0.2mm to 0.5mm diameter are successfully made, and 3D-3C flows are imaged and measured for comparison. The experimental results from different sizes and micro structures to generate the steady-streaming vortices are compared by observing the cross-sectional views from different perspectives of the measured 3-D flow fields, and the flow characteristics and regions influenced by the steady streaming vortices can be obtained. Comparison of the steady-streaming vortices generated by these two kinds of structures show that the bubble structure have better ability in converting oscillatory kinetic energy into the fluid to form steady-streaming vortices. It can form stronger steady-streaming vortices and drive the fluids around the vortices. It also prevents the generation of tiny vortices in the flow field. By analyzing the velocity magnitude of the steady-streaming vortices, it can be found that the vortices generated have the highest velocity in the core region of the vortices, and the strength of the vorticities decreases from the center to the outer region. By drawing the radius of the steady-streaming vortex, the region influenced by the steady-streaming vortex can also be obtained.

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