基于介电电泳的粒子分离微流控芯片的研究

摘要

A dielectrophoresis microfluidic chip applied to particle separation was fabricated,particles were separated efficiently by different dielectric properties.The chip consisted of ITO electrodes based on glassed substrate and PDMS microchannel using MEMS technology.On this basis,the positive and negative dielectrophoresis response of polystyrene microspheres and yeast cells in the medium with a conductivity of 1 μS/cm and an A/C signal voltage of 10 V were measured.The separation conditions of the two kinds of particles were determined.Yeast cells showed negative dielectrophoresis response at 1 ～50 kHz,and show positive dielectrophoresis response at 50 kHz ～ 5 MHz,50 kHz is the crossover frequency.Polystyrene microspheres always show negative dielectrophoresis response at 1kHz～5 MHzo Polystyrene microspheres and yeast cells were separated successful under an A/C signal voltage of 10 V and the frequency of 5 MHz,polystyrene spheres with diameter of 5 μm and yeast were separated,and the separation efficiency reached 92.4％.%文中制备了一种用于粒子分离的介电电泳微流控芯片,利用粒子介电性质不同实现粒子批量、高效分离.采用MEMS工艺,由光刻有电极的ITO玻璃基底和PDMS微通道制备而成.在此基础上,测定了当缓冲溶液的电导率为1 μS/cm、交流信号电压为10 V时聚苯乙烯小球和酵母菌的正负介电泳响应,确定了两种微粒的分离条件:酵母菌细胞在1 ～ 50 kHz时表现负介电泳响应,50 kHz～5 MHz时表现正介电泳响应,50 kHz为交叉频率;聚苯乙烯小球在1 kHz～5 MHz始终表现负介电泳响应.选取10 V、5 MHz交流电压信号作为分离条件,对直径均为5μm的聚苯乙烯小球和酵母菌进行了分离,分离效率达到92.4％.