A three-dimensional microfluidic model based on dielectrophoresis for the separation of blood cells

In recent years, cell-based micro-robots have shown great potential in the biomedical field due to their excellent biocompatibility and precise targeting ability. The primary task for in-depth research on micro-robots based on different cell types is to effectively separate them from the blood. This paper proposes a microfluidic model based on dielectrophoresis for cell separation to achieve the separation of platelets, red blood cells, and white blood cells in the blood. Firstly, a three-dimensional microfluidic model was established using COMSOL Multiphysics software, with electrodes arranged alternately positive and negative to construct the model, and the grid independence was tested to ensure the accuracy and reliability of the proposed model. Secondly, using the dielectric properties of blood cells, an effective separation of various blood cells in the blood was achieved through a size-based hierarchical method. The simulation results showed that blood cells of different sizes had different responses to negative dielectrophoretic forces, causing them to flow out from different exits, thus achieving efficient cell separation. Finally, to further optimize the model, different electrode shapes were designed, and their respective electric field distributions and particle trajectories in the microfluidic channels were calculated. Through quantitative comparative analysis, the separation efficiency and purity of different models were compared, and an effective microfluidic model for separating blood cells was selected, which could further improve the separation efficiency of platelets.