本研究旨在比較兩種三維微流場量測技術-數位離焦微粒影像測速儀 (Digital Defocusing Micro-Particle Tracking Velocimetry, DDμ-PTV) 與數位同軸全像微粒影像測速儀 (Digital In-Line Holographic Micro-Particle Tracking Velocimetry, DIHμ-PTV) 之性能表現。將兩系統建置於倒立式顯微鏡上，透過校正實驗比較兩者之三維重建位置不准度差異，並分別用以拍攝聲射微流體 (Acoustofluidics)之三維穩態射流渦漩影像，再以微粒循跡測速儀 (Particle Tracking Velocimetry, PTV)技術解析其流場並進行探討。對格點陣列校正片使用兩技術進行校正實驗之拍攝與分析結果顯示，使用DDμ-PTV技術與DIHμ-PTV技術可解析之流場體積分別為533 μm × 429 μm × 320 μm及561 μm × 451 μm × 720 μm。此結果顯示當觀測流場長寬大致相同時，DIHμ-PTV技術能解析較大深度範圍之流場。在三維位置不准度的分析結果顯示，DDμ-PTV技術優於光學像差未校正之DIHμ-PTV技術。使用DDμ-PTV與DIHμ-PTV技術的X、Y、Z重建位置不准度分別為0.32 μm、0.37 μm、5.28 μm，以及 2.58 μm、2.48 μm、16.83 μm。而在使用上述兩種技術量測以三角形微結構激發之聲射微流體之三維流場時，PTV循跡分析結果顯示，在分析相同1200張之影像時，DDμ-PTV技術可接起281條微粒軌跡，而DIHμ-PTV技術可以接起311條微粒軌跡。三維速度場分析結果則顯示，DDμ-PTV技術所測得三角形尖端附近的微粒速度約為150 μm/s ~ 220 μm/s，而遠離尖端之微粒速度約為20 μm/s；使用DIHμ-PTV技術測得之微粒速度則分別約為300 μm/s ~ 420 μm/s與40 μm/s。此結果顯示DIHμ-PTV技術因為入光量高，可以使用較短的曝光時間成像因此有較大的速度動態量測範圍。

The purpose of the study is to compare the performances of two volumetric methods for micro-scale flow field measurement - digital defocusing micro-particle tracking velocimetry (DDμ-PTV) and digital in-line holographic micro-particle tracking velocimetry (DIHμ-PTV). The two systems were set up on an inverted microscope, and measurement uncertainties of the reconstructed positions for the two systems were compared through calibration experiments. The two techniques were then applied to measure the three-dimensional steady streaming vortical flows of an acoustofluidic device induced by a triangular micro-structure with particle tracking velocimetry (PTV) technique. The calibration experiment results performed and analyzed with the grid calibration target for both techniques show that the measurable range resolved by DDμ-PTV and DIHμ-PTV were 533 μm × 429 μm × 320 μm, and 561 μm × 451 μm × 720 μm, respectively. These indicates that when the measured flow fields are at approximately the same length and width, the DIHμ-PTV can resolve a larger range of depth position. The uncertainty analysis of the reconstructed 3-D positions shows that DDμ-PTV is better than DIHμ-PTV without correcting the optical abberations. The X, Y, and Z position uncertainties were 0.32 μm, 0.37 μm, and 5.28 μm for the DDμ-PTV and 2.58 μm, 2.48 μm, and 16.83 μm for DIHμ-PTV, respectively. When the two techniques were applied to measure the 3-D flow fields of the acoustofluidic device induced by a triangular structure, the tracking results of PTV show that for analyzing the 1200 images, DDμ-PTV can track 281 particle tracks while DIHμ-PTV can track 311 particle tracks. 3-D velocity field analysis results show that the velocity of particles measured using DDμ-PTV near the triangular tip is about 150 μm/s ~ 220 μm/s, while the velocity of particles far from the tip is about 20 μm/s, respectively. On the other hand, results with DIHμ-PTV were about 300 μm/s ~ 420 μm/s and less than 40 μm/s, respectively. These results show the DIHμ-PTV has larger velocity dynamic range because of the higher light input and shorter exposure time.

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