Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA.
Electrophoresis. 2021 Mar;42(5):644-655. doi: 10.1002/elps.202000222. Epub 2021 Feb 1.
Dielectrophoresis is a robust approach for the manipulation and separation of (bio)particles using microfluidic platforms. We developed a dielectrophoretic corral trap in a microfluidic device that utilizes negative dielectrophoresis to capture single spherical polystyrene particles. Circular-shaped micron-size traps were employed inside the device and the three-dimensional trap stiffness (restoring trapping force from equilibrium trapping location) was analyzed using 4.42 μm particles and 1 MHz of an alternating electric field from 6 V to 10 V . The trap stiffness increased exponentially in the x- and y-direction, and linearly in the z-direction. Image analysis of the trapped particle movements revealed that the trap stiffness is increased 608.4, 539.3, and 79.7% by increasing the voltage from 6 V to 10 V in the x-, y-, and z-direction, respectively. The trap stiffness calculated from a finite element simulation of the device confirmed the experimental results. This analysis provides important insights to predict the trapping location, strength of the trapping, and optimum geometry for single particle trapping and its applications such as single-molecule analysis and drug discovery.
介电泳是一种利用微流控平台对（生物）颗粒进行操作和分离的强大方法。我们在微流控设备中开发了一种介电泳围栏陷阱，该陷阱利用负介电泳来捕获单个球形聚苯乙烯颗粒。设备内部采用圆形微尺寸陷阱，并使用 4.42μm 颗粒和 1MHz 的交流电场（6V 至 10V）分析了三维陷阱刚度（从平衡捕获位置恢复捕获力）。在 x-和 y-方向上，陷阱刚度呈指数增长，在 z-方向上呈线性增长。对捕获颗粒运动的图像分析表明，在 x-、y-和 z-方向上，电压从 6V 增加到 10V，陷阱刚度分别增加了 608.4、539.3 和 79.7%。对设备的有限元模拟进行的分析验证了实验结果。该分析为预测捕获位置、捕获强度以及用于单颗粒捕获及其应用（如单分子分析和药物发现）的最佳几何形状提供了重要的见解。
