Continuous particle separation in a serpentine microchannel via negative and positive dielectrophoretic focusing
Continuous particle separation in a serpentine microchannel via negative and positive dielectrophoretic focusing
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DOI：
10.1088/0960-1317/20/6/065011
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发表时间：
2010-06-01
影响因子：
2.3
通讯作者：
Xuan, Xiangchun
中科院分区：
文献类型：
--
作者：
Church, Christopher;Zhu, Junjie;Xuan, Xiangchun
在微流控器件中，介电泳法(DEP)被广泛应用于细胞和颗粒的聚焦和分离。这项工作首先通过改变悬浮液的电导率，展示了蛇形微通道中颗粒的正负向介电聚焦。由于沟道转向诱导的介质电泳力，当颗粒的电导率低于(即负DEP)或高于流体的电导率(即正DEP)时，颗粒被聚焦到通道的中心线或侧壁。然后，将蛇形微通道中的这些独特的介电聚焦现象结合在一起，实现不同尺寸和电导率的颗粒之间的连续分离。这种分离消除了在基于DEP的分离技术中通常需要的通道内微电极或微绝缘体的制造。建立了预测颗粒运动的数值模型，模拟结果与观测到的颗粒聚焦和分离行为吻合较好。
Dielectrophoresis (DEP) has been widely used to focus and separate cells and particles in microfluidic devices. This work first demonstrates negative and positive dielectrophoretic focusing of particles in a serpentine microchannel by changing only the electric conductivity of the suspending fluid. Due to the channel turn-induced dielectrophoretic force, particles are focused to either the centerline or the sidewalls of the channel when their electric conductivity is lower (i.e. negative DEP) or higher (i.e. positive DEP) than that of the fluid. These distinctive dielectrophoretic focusing phenomena in a serpentine microchannel are then combined to implement a continuous separation between particles of different sizes and electric conductivities. Such separation eliminates the fabrication of in-channel microelectrodes or micro-insulators that are typically required in DEP-based separation techniques. A numerical model is also developed to predict the particle motion, and the simulation results agree reasonably with the observed particle focusing and separation behaviors.