基于PCB工艺的交流介电电泳芯片粒子富集与分离技术研究

发布时间：2018-05-20 18:22

本文选题：介电电泳 + 印制电路板　；参考：《重庆大学》2015年硕士论文

【摘要】：介电电泳技术是微流控系统中实现粒子富集与分离的关键技术之一;与机械或光学等其他方法相比,具有操作方便、响应速度快、非接触、易于实现微型化和自动化等优点,在一些大分子微粒及生物细胞的准确捕获、富集、分离及输运研究中具有极大的潜力。现有介电泳芯片大多通过微机电系统(Micro-Electro-Mechanical System,MEMS)技术加工而成,但该工艺设备昂贵、工序复杂,目前不能实现批量化生产,限制了芯片的推广应用。而印制电路板(Printed Circuit Board,PCB)工艺具有低成本、可批量生产、便于封装等优点,研究采用PCB工艺加工介电泳芯片并实现粒子操控具有重要意义与实用价值。本文针对PCB工艺分辨率存在局限性的问题,围绕基于PCB工艺的交流介电泳芯片优化设计与利用该芯片实现粒子富集与分离的原理和实验展开了研究。具体包括以下几个方面的工作:①分析了介电电泳技术操控粒子富集与分离的原理。对非均匀电场作用下悬浮于电介质溶液中的中性微粒进行了受力分析,得到介电泳力操控粒子运动的主要影响因素。②建立叉指式介电泳芯片的二维仿真模型,在PCB工艺分辨率允许的条件下,模拟了芯片中电场的分布情况。进一步分析了芯片中粒子受到介电泳力的大小和方向,获得了通道高度、电极特征参数(电极宽度/间距)及电压与介电泳力大小的关系,优化了介电泳芯片的电极参数。③基于Laplace方程,采用傅里叶级数分析方法,推导了影响介电电泳分离的关键参数—粒子悬浮高度的表达式;通过与仿真结果对比,对计算结果进行了验证。进一步分析得到电极厚度对粒子悬浮高度的影响随着电极厚度的增大而增大。④通过PCB工艺制作了电极宽度/间距为100μm的叉指式介电泳芯片,以聚苯乙烯微球和酵母菌细胞为样品,完成了粒子富集与分离的操控实验;通过图像计数方法对富集效果进行了评价。结果表明:频率为100k Hz~10MHz时,聚苯乙烯微球受负介电泳力作用电极中心或电极间距中心富集以及某确定高度平面上富集,富集后粒子个数是富集前的三倍;而酵母菌细胞在该频率范围内受正介电泳力作用在电极边缘富集,粒子个数是富集前的两倍。利用两种粒子受介电泳力方向不同,实现了两种样品在三维空间上分离。
[Abstract]:Dielectric electrophoretic technology is one of the key techniques to realize particle enrichment and separation in microfluidic system. Compared with other methods, such as mechanical or optical, it has the advantages of easy operation, fast response, non-contact, easy to realize miniaturization and automation, etc. It has great potential in the accurate capture, enrichment, separation and transport of some macromolecular particles and biological cells. Most of the existing microelectrophoretic chips are fabricated by Micro-Electro-Mechanical system MEMS (Micro-Electro-Mechanical system MEMS) technology, but the process equipment is expensive and the working procedure is complex, so it is not possible to realize mass production at present, which limits the popularization and application of the chip. The printed Circuit board (PCB) process has the advantages of low cost, mass production and easy packaging. It is of great significance and practical value to study the use of PCB process to process the dielectric electrophoresis chip and realize particle control. Aiming at the limitation of the resolution of PCB process, the optimization design of AC medium electrophoresis chip based on PCB process and the principle and experiment of particle enrichment and separation by using this chip are studied in this paper. It includes the following aspects: 1 analyses the principle of dielectric electrophoretic technique to control the enrichment and separation of particles. The force of neutral particles suspended in dielectric solution under the action of non-uniform electric field was analyzed, and the main influencing factors of particle movement were obtained. 2. The two-dimensional simulation model of cross finger dielectric electrophoretic chip was established. The distribution of the electric field in the chip is simulated under the condition of the resolution of the PCB process. The relationship of channel height, electrode characteristic parameters (electrode width / spacing) and voltage with the dielectric electrophoresis force was obtained. The electrode parameters of dielectric electrophoretic chip based on Laplace equation were optimized. The expression of particle suspension height, the key parameter affecting the separation of dielectric electrophoresis, was derived by Fourier series analysis, and the results were compared with the simulation results. The calculation results are verified. The effect of electrode thickness on the suspension height of particles increased with the increase of electrode thickness. A cross finger electrophoresis chip with electrode width / spacing of 100 渭 m was fabricated by PCB process. Using polystyrene microspheres and yeast cells as samples, the experiment of particle enrichment and separation was completed, and the effect of enrichment was evaluated by image counting method. The results show that when the frequency is 100k Hz~10MHz, the polystyrene microspheres are enriched by negative dielectric electrophoretic force at the electrode center or electrode spacing center and on a certain height plane, and the number of particles after enrichment is three times as much as that before enrichment. The yeast cells were enriched at the electrode edge by positive electrophoretic force in this frequency range, and the number of particles was twice as large as that before enrichment. The separation of the two samples in three dimensional space was realized by using the different directions of the two kinds of particles subjected to dielectric electrophoresis.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN41

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