Continuous sorting and separation of microparticles by size using AC dielectrophoresis in a PDMS microfluidic device with 3-D conducting PDMS composite electrodes
Continuous sorting and separation of microparticles by size using AC dielectrophoresis in a PDMS microfluidic device with 3-D conducting PDMS composite electrodes
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DOI：
10.1002/elps.201000087
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发表时间：
2010-08-01
期刊：
影响因子：
2.9
通讯作者：
Lam, Yee Cheong
中科院分区：
文献类型：
--
作者：
Lewpiriyawong, Nuttawut;Yang, Chun;Lam, Yee Cheong
软光刻技术允许开发许多基于pdm的微流体设备，用于操纵颗粒和细胞。然而，由于金属与PDMS之间的附着力较弱，将金属电极与基于PDMS的通道结构集成是具有挑战性的。为了克服这一问题，我们开发了一种新的基于PDMS的微流控装置，该装置采用交流电介质（DEP），以三维导电PDMS复合材料作为侧壁电极，按尺寸连续分选和分离微颗粒。该复合电极是由银粉与PDMS凝胶混合而成的，该复合电极可以很容易地与PDMS微通道集成。此外，侧壁电极还允许DEP力三维分布，从而增强了整个通道区域的DEP效应。这种基于pdm的微流控装置可以连续分选和分离10和15 μ m的颗粒，也可以分离5和10 μ m的颗粒。结合实验结果，基于拉格朗日方法的粒子运动轨迹分析，揭示了在流体动力和DEP力的作用下，微颗粒在pdm微流控装置中的输运情况。
Soft lithography technology allows for the development of numerous PDMS-based microfluidic devices for manipulation of particles and cells. However, integrating metallic electrodes with PDMS-based channel structures is challenging due to weak adhesion between metal and PDMS. To overcome this issue, we develop a new PDMS-based microfluidic device for continuous sorting and separation of microparticles by size using AC dielectrophoresis (DEP) with 3-D conducting PDMS composites as sidewall electrodes. The composites are synthesized by mixing silver powders with PDMS gel and such composite electrodes can easily be integrated with the PDMS microchannels. Furthermore, the sidewall electrodes also allow DEP forces to distribute three dimensionally, thus enhancing DEP effects in the entire region of channels The capability of such PDMS-based microfluidic device is demonstrated for continuously sorting and separating 10 and 15 mu m particles, and also for separating 5 from 10 mu m particles. Together with experimental results, analysis of particle's trajectory based on Lagrangian approach provides insights into how microparticles transport under the effects of hydrodynamic and DEP forces in the present PDMS-based microfluidic device.