基于介电电泳的粒子分离微流控芯片实验  

Particle Separation Microfluidic Chip Experiment Based on Dielectrophoresis

作　　者：吴菲[1,2] 曾一笑 樊磊[1,2] 谭秋林[1,2] 孙东[1,2] 

机构地区：[1]中北大学电子测试技术重点实验室,太原030051 [2]中北大学仪器科学与动态测试教育部重点实验室,太原030051

出　　处：《微纳电子技术》2017年第10期694-698,705,共6页Micronanoelectronic Technology

基　　金：山西省基础研究项目(2014011021-3)

摘　　要：根据介电电泳原理,设计了一种梯形叉指的微电极结构,用于粒子的连续分离。首先利用COMSOL软件分析梯形叉指电极的电场分布,确定芯片中电场强度最大值和最小值的位置,并分析粒子在微流控芯片中的受力情况。然后,采用微电子机械系统(MEMS)工艺,以氧化铟锡(ITO)电极玻璃为基底制备了粒子连续分离的芯片。通过实验选取通道障碍的最优尺寸,最后用聚苯乙烯小球和酵母菌细胞为样本进行实验并证明,当混合粒子溶液以3μm/min的速度通过微通道障碍时,由于惯性聚焦全部粒子偏向微通道上方运动,施加6 V的峰值电压和20 kHz的交流信号,此时聚苯乙烯小球和酵母菌细胞皆是负介电泳响应,聚苯乙烯小球所受介电泳力大于流体力便向微通道下方进行偏移,而酵母菌细胞所受流体力大于负介电泳力,其仍然在微通道上方,聚苯乙烯小球和酵母菌细胞分离,分离效率可达到92.8%。According to the principle of dielectrophoresis, the trapezoid interdigital microelectrode structure was designed to use for the continuous separation of particles. The COMSOL software was used to analyze the electric field distribution of trapezoid interdigital electrodes and determine the positions of the maximum and minimum electric field intensity on the chip, and the force of the particles in the microfluidic chip was analyzed. With indium tin oxid （ITO） electrode glass as the substrate, the particles continuous separation chip was prepared by the micro-electromechani- cal system （MEMS） technology. The optimal size of channel obstacles was selected through the experiment. The experiment was completed with polystyrene spheres and yeast cells as samples. It is proved that when the mixed particles solution gets through the microchannel barriers in a speed of 3 μm/min, all the partlctes in the microchannel move above due to the inertial focus.When the AC signal with the peak voltage of 6 V and 20 kHz is applied, the polystyrene spheres and yeast cells are negative dieleetrophoresis responses. The dielectrophoretic forces of polysty- rene spheres in the microchannel are larger than the fluid force, and they shift below. While the yeast cells in the microchannel are still above for the suffered fluid force greater than the negative dielectrophoresis force, thus the polystyrene spheres and yeast cells are separated, and the sepa- ration efficiency can reach 92.8 %.

关 键 词：微流控芯片 连续分离 惯性聚焦 介电电泳 微电子机械系统(MEMS) COMSOL 

分 类 号：O35[理学—流体力学]