摘要
近年微機電技術日漸成熟，利用微機電製程技術製作微流體晶片基礎研究已經有相當多的成果，而本文研究目的在於利用微機電技術製作微流體晶片，將複雜的微血管網絡簡化為兩種類型的幾何形狀(直管、彎管)，於其上加上奈米孔隙，來分析微流道幾何設計對於奈米顆粒陷入奈米流道的比例影響的基礎研究。 本實驗利用微質點影像測速法(μPIV)觀測微流道其速度分布情況，並且利用套裝模擬軟體CFD-ACE+，結合Flow Module與Spray Module來模擬求解奈米顆粒在微流道中的運動。 由目前的實驗結果顯示，當奈米粒子在微流道運動時，其受到布朗運動的力量最為顯著，並且和奈米粒子的大小有著一關係式。在陷入比例方面，在彎管前段部分，奈米粒子陷入內側的比例高於外側，而彎管後段部分，奈米粒子陷入外側的比例則是高於內側。並且當固定奈米粒子大小時，曲率半徑越大的設計所擁有的陷入比例越高，而在相同曲率半徑的設計，當奈米粒子尺寸縮小，可得較高的陷入比例。應用在腫瘤治療方面，我們希望可透過陷入比例的結果以提高癌症標靶治療的投藥效率。
並列摘要
In this paper, we have (1) built a micro flow network that mimics micro vessels and visualized the flow inside utilizing both experimental and CFD approaches, (2) developed a model, which considering both the inertial forces caused by flow convection and the diffusion resulting from Brownian motion, to evaluate the entrapment probability of nanoparticles with various particle sizes and channel geometries from micro flow field into nanochannels.. The micro flow network was fabricated by photolithography process and Deep Reactive Ion Etching (DRIE) process. Hundreds nanometer wide nano-gaps located around curved silicon micro-channels were arranged for simulating the geometry of leaky blood vessels in tumors. The nano-gap was about 600 nm in both width and depth, and fabricated by focus ion beam (FIB) process. Finally, the chip was sealed with a Pyrex glass substrate by anodic bonding technique. Micro particle image velocimetry (μPIV) is then employed to visualize the particle-laden flow inside the microfluidic channels. By dual pulse μPIV, the particle images are recorded at two specific moments with continuous illumination. In the experimental results, the spatial resolution of about 2 μm is employed to resolve the near-wall flow field with 50% interrogation spot overlapping by using μPIV. The most significant deviation is about 5% between the experimental and simulation results, which implies excellent agreement and brings out the evidence in utilizing simulation for more detailed study on the flow behaviors of nano- particles. We found that the working fluid passing through the inner side of the curved channel was apparently accelerated. The distortion in velocity profile could potentially lead to the increase of particle concentration, and facilitate the entrapment of particles into the nano-gap. And finally we used Stokes-Einstein equation to estimate the entrapment probability of nanoparticles with various particle sizes and channel geometries.