| Summary: | 碩士 === 國立臺灣大學 === 應用力學研究所 === 93 === This thesis presents microfluidic devices to perform cell lysis using electroporation with planar and 3D electrode designs. The goal of the study is to compare the lysis performance of the two electrode geometries. The planar electrode design is pointed in shape (gap is 20μm, width of base 50μm) and that of 3D electrode are circular cylinders (diameter and height are 50μm, gap between cylinders 20μm), which are fabricated by electroforming. Pulse signal is used for electroporation, with amplitude of 10V and duration of 100μs – long compared to membrane charging time of 10-1000ns. The commercial software FEMLAB and MATLAB are used for simulation of electric field. In the experiment, leukocyte is used as lysis element.
Computational results show that the electric field of 3D electrode geometry is, indeed, more uniform than that of planar configuration, resulting in effective volume ratio — volume which electric field is sufficient for cell lysis to net volume — of the 3D geometry is substantially larger than that of the planar design. Also, the efficacy of lysing depends not only on the electric field but, more importantly, on the temporal extend which the cell is exposed to the field strength required for lysis as the cell proceeds downstream.
Experimentally, multi-pores are observed on leukocyte lysed with 3D electrodes and just single pore with planar electrodes. This is believed to be due to more uniform electric field of 3D electrodes than that of planar electrodes. Intracellular elements are extracted through the membrane as observed by increased intensity of Trypan blue when diluted by saline solution. We also demonstrate the lysing percentages at same flow velocity to explain the performance of 3D electrode is superior to that of planar electrode.
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