Cheri Mohammad Sadegh, Latifi Hamid, Khashei Hesamodin, Seresht Mohsen Jamshidi
Laser and Plasma Institute, Shahid Beheshti University, Tehran, Iran; Department of Physics, Shahid Beheshti University, Tehran, Iran.
Electrophoresis. 2014 Dec;35(24):3523-32. doi: 10.1002/elps.201400349. Epub 2014 Nov 20.
Focusing and separation of microparticles in a complex mixture have had wide applications in chemistry, biology, medicine, etc. This work presents a numerical and experimental investigation on focusing and continuous separation of microparticles in a geometrically optimized arrangement of steps in the form of a staircase using insulator-based dielectrophoresis (iDEP) mechanism. First, a detailed finite element analysis was performed on important parameters in the focusing and separation of microparticles, such as geometry of stair-shaped microchannel, total voltage, and voltage difference applied to reservoirs. The optimum parameters obtained from numerical analysis were used for experimental work. Theoretically, predicted microparticle trajectories are in good agreement with experimentally observed ones. Experimental and numerical results show that the performance of focusing of microparticles enhances with growth of the total voltage (in a constant voltage difference) and decreases with voltage difference. The fabricated iDEP microchip enhances the performance of focusing and separation of microparticles due to its stair-shaped microchannel and therefore operates at low DC total applied voltages of 90-110 V.
在复杂混合物中对微粒进行聚焦和分离在化学、生物学、医学等领域有着广泛应用。这项工作针对基于绝缘体的介电泳（iDEP）机制，对呈阶梯形式几何优化排列的台阶中微粒的聚焦和连续分离进行了数值和实验研究。首先，对微粒聚焦和分离中的重要参数进行了详细的有限元分析，如阶梯形微通道的几何形状、总电压以及施加到储液器上的电压差。从数值分析中获得的最佳参数被用于实验工作。理论上，预测的微粒轨迹与实验观察到的轨迹吻合良好。实验和数值结果表明，在恒定电压差下，微粒聚焦性能随总电压的增加而增强，随电压差的增加而降低。所制造的iDEP微芯片由于其阶梯形微通道而提高了微粒聚焦和分离的性能，因此在90 - 110 V的低直流总施加电压下运行。
