Cell focusing and separation is a prerequisite for several biological applications. Among these technologies that can achieve the operation, dielectrophoresis (DEP) has been widely used due to its non-contact, label-free and easy-to-operate advantages. In this paper, we designed a microchip that integrates 3D electrodes and wavy microchannel for cell focusing and separation. The 3D electrodes act as not only the electrodes but also as the microchannel walls. The wavy microchannel enables 3D electrodes to generate electric field gradient required by DEP force in the entire microchannel. Cells can be focused and separated under the synergistic effect of DEP and fluidic forces. We have demonstrated the feasibility of the microchip through numerical simulations and experiments. And we validated our approach by demonstrating focusing and separation of A549 and HeLa cells. According to the electrical differences of cells, in the range of 61–99 kHz, the two types of cells can be focused into three streams under the action of positive and negative DEP force to achieve cell separation. With the increase of the voltage amplitude to 10 V, the width of the cell streams was focused to about 30 μm, which can improve the effect of cell separation, the separation efficiency of A549 and HeLa can reach 91.2% and 95.1%, respectively. The proposed microchip is expected to provide a new pathway for designing an effective cell focusing and separation platform.

细胞聚焦和分离是多种生物学应用的先决条件。在这些可实现手术的技术中，介电电泳（DEP）以其非接触、免标记和易于操作的优点得到了广泛的应用。在本文中，我们设计了一种集成 3D 电极和波浪形微通道的微芯片，用于细胞聚焦和分离。3D 电极不仅充当电极，还充当微通道壁。波浪形微通道使 3D 电极能够在整个微通道中产生 DEP 力所需的电场梯度。在 DEP 和流体力的协同作用下，细胞可以被聚焦和分离。我们已经通过数值模拟和实验证明了微芯片的可行性。我们通过展示 A549 和 HeLa 细胞的聚焦和分离验证了我们的方法。根据细胞的电学差异，在61-99kHz范围内，两种细胞在正负DEP力的作用下可聚集成三股流，实现细胞分离。随着电压幅度增加到 10 V，细胞流的宽度集中到大约 30μ m，可提高细胞分离效果，A549和HeLa的分离效率分别达到91.2%和95.1%。所提出的微芯片有望为设计有效的细胞聚焦和分离平台提供一条新途径。