DC-dielectrophoretic separation of microparticles using an oil droplet obstacle
DC-dielectrophoretic separation of microparticles using an oil droplet obstacle
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DOI：
10.1039/b513183a
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发表时间：
2006-02-01
期刊：
影响因子：
6.1
通讯作者：
Li, DQ
中科院分区：
文献类型：
--
作者：
Barbulovic-Nad, I;Xuan, XC;Li, DQ
在接下来的实验研究中，我们演示并检验了一种新的介电泳颗粒分离方法。目前的无电极介电泳（DEP）分离技术利用直流或低频交流磁场中的绝缘固体障碍物，而这种新方法利用油滴作为两个电极之间的绝缘障碍。当颗粒在由液滴局部形成的非均匀直流场中运动时，它们受到与体积线性相关的负DEP力，这允许颗粒按尺寸分离。由于液滴的大小可以动态改变，因此电场梯度和DEP力可以很容易地控制和调节到各种分离参数。通过调节液滴大小，在80v cm(-1) ~ 240v cm（-1）的电场强度范围内，在PDMS微流控芯片中成功分离了1 μ m、5.7 μ m和15.7 μ m三种不同直径的颗粒。由于电场梯度是比外加电压更重要的粒子识别参数，因此在低场强下实现了非常有效的分离。通过利用低强度场和自适应场梯度，该方法也可以应用于一般对高电位非常敏感的生物样品的分离。
A new dielectrophoretic particle separation method is demonstrated and examined in the following experimental study. Current electrodeless dielectrophoretic (DEP) separation techniques utilize insulating solid obstacles in a DC or low-frequency AC field, while this novel method employs an oil droplet acting as an insulating hurdle between two electrodes. When particles move in a non-uniform DC field locally formed by the droplet, they are exposed to a negative DEP force linearly dependent on their volume, which allows the particle separation by size. Since the size of the droplet can be dynamically changed, the electric field gradient, and hence DEP force, becomes easily controllable and adjustable to various separation parameters. By adjusting the droplet size, particles of three different diameter sizes, 1 mu m, 5.7 mu m and 15.7 mu m, were successfully separated in a PDMS microfluidic chip, under applied field strength in the range from 80 V cm(-1) to 240 V cm(-1). A very effective separation was realized at the low field strength, since the electric field gradient was proved to be a more significant parameter for particle discrimination than the applied voltage. By utilizing low strength fields and adaptable field gradient, this method can also be applied to the separation of biological samples that are generally very sensitive to high electric potential.