【作者】 李霞；

【导师】 刘冲；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2018， 硕士

【摘要】 聚合物即时检测芯片因为其制造成本低、分析准确、溶剂消耗量小和良好的生物兼容性而得到广泛关注。而聚合物即时检测芯片仅依靠自身表面张力不足以驱动液流前进,基于此本论文以热塑性微流控即时检测芯片为基础,通过表面涂层改性方式对芯片通道进行亲水化改性,并运用通道侧壁疏水划线工艺解决亲水改性后产生的边缘效应问题。本文主要研究内容如下:(1)基于基础浸润理论,研究了矩形通道毛细管驱动液流所需表面条件并优化溶胶配比。本文对毛细管内的流动理论详加阐述,并针对实验芯片通道尺寸及物理性质对液体流速控制理论加以计算,初步估算出表面亲水处理接触角范围为30-35°;通过实验论证,得到针对本特定芯片的最佳溶胶体系配比。(2)提出并完善了即时检测芯片通道的亲水涂膜工艺。针对即时检测芯片亲水涂层工艺设计了即时检测芯片专用夹具,搭建了提拉平台。运用提拉平台对工艺参数进行了实验探究和优化得出,当溶胶粘度较小时提拉速度与温度并未对成膜产生很大影响,增加了该工艺适用环境范围;经过对亲水涂层后的芯片进行表面的成膜质量检测及流动性检测,检测结果表明亲水涂层与基底之间有很好的粘附性,且膜厚在百纳米级,不会对芯片表面微结构产生影响;芯片通道进行亲水涂膜后表面接触角片间与片内差异性较小;亲水涂层后芯片血清流速达到理论计算及检测要求。(3)深入分析了边缘效应的形成原理并提出解决办法,研究了其工艺参数。采用侧壁及底面疏水划线的方法解除拐角流形成的条件进而消除边缘效应;运用疏水划线溶液分别为液体石蜡,硅油和中性树脂,综合工艺适用条件选择硅油作为疏水划线溶液;实验论证了疏水划线宽度对液体流动的影响,当硅油用作疏水划线的溶液时,划线宽度范围为60-90μm时,液体流动前端曲率半径为0.29 mm-0.87 mm,可以保证液体流动前端呈现稳定的凸液面;测试了亲水涂膜及疏水划线两工艺对荧光检测的影响,荧光检测实验结果表明,即时检测芯片表面亲水涂膜与侧壁疏水划线处理后,心肌肌钙蛋白I(cTnI)检测峰值均达到25000以上,可以用于cTn I检测。更多还原

【Abstract】 The polymer microfluidic chips because of its low fabrication cost,high analytical performance,solvent consumption,and the advantages of good biological compatibility have gotten widespread attention.It’s not enough to drive the liquid flow forward that only rely on the surface tension of the chip material itself.Based on this,the hydrophilic coating is used to enhance the surface hydrophilicity of specific thermoplastic microfluidic chips.And the problem of edge effect caused by hydrophilic modification is solved.The main contents of this paper are as follows:(1)Based on the basic infiltration theory,the surface contact angle of rectangular channel capillary flow and the sol ratio were optimized and calculated.In this paper,the capillary flow theory is described.The liquid flow rate control theory was calculated according to the channel size and physical properties of the experimental chips and the surface hydrophilic treatment of the contact angle range was estimated of 30-35°initially.Through the experimental demonstration,the best ratio of sol-gel system for this chip was prepared.(2)The hydrophilic coating process of POCT chips had been proposed and improved.The processing platform was built and debugged,and the process parameters were determined by experiments.The design and production of the specific chip fixture based on the experimental POCT chip was finished.The process parameters were experimentally explored and optimized by using the pulling device.It is known from the experimental results that the pulling speed and the temperature did not have a great influence on the film formation while the viscosity of the sol was relatively small.The results show that it has good adhesion between the hydrophilic coating and the substrate,and the film thickness is in the order of 100 nanometers,which does not affect the microstructure of the chip surface.The inter-chip difference and the differences between chips of contact angle after hydrophilic coating is small.The serum flowing rates meet the theoretical calculations and testing requirements,and the flowing rates are stable after hydrophilic coating.(3)The formation mechanism of edge effect was analyzed and the solution was proposed and the process parameters were studied.Adopting the method of hydrophobic scribing on the side wall and bottom surface to eliminate the condition of corner flow and eliminate the edge effect.In this experiment,the solutions of hydrophobic marking line are liquid paraffin,silicone oil and neutral resin.And considering the hydrophobicity,the scope of application and the viscosity of the solution,silicone oil is selected as the hydrophobic marking line solution.Experiments demonstrate the effect of hydrophobic marking line width on the liquid flow.While the silicone oil was used as the solution of hydrophobic marking line and the range of marking line width was 60-90 μm,the radius of curvature of the liquid front is 0.29 mm-0.87 mm and it showed a stable convex liquid front.Fluorescence test results showed that after the hydrophilic coating and hydrophobic marking line,the peak values of cardiac troponin I(cTn I)were all above 25000,and the surface treatment methods can be used for cTnI testing.更多还原