标题: | 椭圆微型模穴之微液体填充研究 Analysis on Filling Process in Oval Disk-Shaped Micro Chambers of Composite Materials at Different Aslope Angle |
作者: | 刘懋勋 Mao-Shiun Liu 林振德 Jenn-Der Lin 机械工程学系 |
关键字: | 微流体;微粒子影像测速法;micro fluidic;PIV;PDMS |
公开日期: | 2005 |
摘要: | 本论文之研究目的在于制作椭圆模穴为主之微流体装置,并藉由实验观测表面张力、附着力、惯性力对液体填充过程中之影响。实验中,流道制作方式有二,一为PDMS翻模而成,另一为以MEMS技术于晶圆上蚀刻流道;根据伟伯数的变化、模穴大小、模穴旋转角、改变椭圆模穴壁面材质和化学处理改变壁面性质,探讨波前与其流动现象,并且使用微粒子影像测速法(PIV)重现会包围气泡模穴填充过程之速度,藉以厘清会发生包围气泡前后实际流动状态。 实验结果显示,容易在模穴产生气泡包覆现象之情况如下: 1.伟伯数相同,椭圆模穴旋转后,越靠近进口流道时。2.椭圆模穴旋转角相同的,伟伯数越高时。3.伟伯数相同,PDMS模穴以PDMS材质封装比以玻璃封装时更易包覆气泡。4.伟伯数及模穴材质相同,相同面积但形状较宽阔的模穴。另外在微粒子影像测速法过程中发现在弯角大的模穴中,因为进口惯性力被表面张力抵销后,速度向量会在波前呈现均匀的分布,导致填充时液面不足以到达模穴角落填充,造成最后的包覆气泡现象。 另本研究中,尚有以化学处理法处理,改变已封装好之模穴内部亲疏水性。针对PDMS模穴而言,实验中的氧电浆再处理法、界面离子活性剂处理法,均会使原本是疏水性质的模穴内壁转变为较亲水。研究结果显示,能使模穴内变亲水的效果,氧电浆再处理法最佳、HEMA处理法最差。针对silicon材料的流道而言,通入等向性蚀刻液TMAH后,能再度蚀刻模穴底面,因为模穴内部非平滑表面,所以比较蚀刻处理前的模穴、处理15分钟的模穴、处理30分钟的模穴的填充结果,因模穴底部表面型态的变化,会出现疏水、亲水、相对疏水的现象。 The purpose of this thesis is to manufacture oval disk-shaped micro fluidic device for observation and also to examine the effect of surface tension, adhesive and inertial force in the filling process. Two methods to manufacture micro channels and micro chambers in this experiment are PDMS molding process and MEMS technology fabricating on the wafer. The liquid filling process is analyzed at variance value the Weber number, size of the chambers, aslope angle of the chambers, associated with the changes in materials of the walls of the micro chambers, and the chemical changes in processing. Furthermore, in order to clarify the actual circumstance of flowing before bubble entrapped and after, PIV is adopted in this experiment for reconstructing the speed distribution of filling in the bubble-entrapped chambers. The result of the experiment shows some circumstances when bubble entrapment occurred: 1. With the same Weber number, the degree between the chambers and the inlet channel decreased. 2. With the same degree between the chamber and the inlet channel, the Weber number increased. 3. The PDMS micro chambers package with PDMS sheet was easier than that with glass sheet. 4. With the same Weber number and the same property of the wall in the chamber, the superficies of the chamber was equivalent but the shape of the chamber was different. In addition, inertia in the inlet channel was offset by the surface tension in big curve chambers, and the speed quantities would spread evenly in the front shapes. Consequently, front shapes failed for reaching chamber corners and filling, and bubble entrapment occurred. Chemical treatment is also used to change the hydrophilic and hydrophobic quality inside the packaged chambers in this experiment. In regard to PDMS chambers, surfactant and treatment O2 plasma for the second time changed the hydrophobic chamber walls into somewhat hydrophilic. Moreover, to make chamber walls become hydrophilic, treatment O2 plasma is better than treatment HEMA in comparison with treatment HEMA in references. In regard to silicon channel, pouring TMAH would etch the bottom of the chambers once more. Inside the chambers was not smooth; when comparing the chamber walls used treatment TMAH for 15minutes and 30minutes with those had not used treatment TMAH, different filling phenomenon would appear while pouring water in chambers. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009314543 http://hdl.handle.net/11536/78517 |
显示于类别: | Thesis |
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