Study on the Influence of Gravity, Surface Tension and Surface Roughness on Microfluidic Flow Time

• Main Authors: Hsiu-Hui Chiu, 邱綉惠
• Other Authors: Wen-Ren Jong
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/42896580398713900002

碩士 === 中原大學 === 機械工程研究所 === 94 === Due to the great advancement in fields of electron, biomedical, communication and aerospace technology, the size in micromachining technology has progressed from millimeter to micrometer and even to nanometer by increasing demands of high added value and high output products. In addition, the micro system can be applied in many industries such as semi-conductor, bio-medical, chemical, energy and photoelectric industries. Therefore, the filling behavior, driving principle, and control of flowing caused by capillarity phenomena become crucial. In this paper, flows in rectangular microchannels driven by capillary force and gravity are discussed. The theoretical mathematical model of flow in microchannel driven by capillary force and gravity is formulated from the Navier-Stokes Equations. A close form solution to predict flow time was developed, and experiments have been performed to investigate and verify the flow times in microchannel. From the results, the predicted flow times show reasonably good agreement with the corresponding experimental flow times. Moreover, when the microchannel height is small, the effects of gravity force becomes less obvious, namely the capillary becomes the dominate source to drive microfluidic. Besides, the influence of surface roughness in microchannel is studied, and three different methods of machining were used to manufacture those microchannels, and experiments have been performed to investigate and verify the flow times in microchannel. From the results, the surface roughness increased, then the flow time is less, and the flow-front of microfluidic becomes more unsteady.