Dielectrophoresis-Based Blood Plasma Extraction using Two-Layer Conducting-PDMS Microelecrodes

Plasma is the most reliable and convenient source of disease diagnostic biomarkers, which is widely used in the point-of-care diagnosis. However, before further analysis of biomarkers, plasma needs to be extracted from the blood. In this paper, a microfluidic chip for blood plasma separation using negative dielectrophoresis (nDEP) force at high conductivity was studied. The 3D electrode made of AgPDMS can produce continuous and efficient DEP force in the flow channel, which can achieve plasma extraction with nDEP force under high conductivity and low manufacturing cost. Using this method, the blood plasma can be separated continuously at 0.06 ml/h in diluted blood with 2.5% hematocrit (Hct), and the purity is beyond 95%. We also explore the separation efficiency of the device under different voltage and different cell loading density.