Electroporation is defined as cell membrane permeabilization under the application of electric fields. The mechanism of hydrophilic pore formation is not yet well understood. When cells are exposed to electric fields, electrical stresses act on their surfaces. These electrical stresses play a crucial role in cell membrane structural changes, which lead to cell permeabilization. These electrical stresses depend on the dielectric properties of the cell, buffer solution, and the applied electric field characteristics. In the current study, the effect of electric field frequency on the electrical stresses distribution on the cell surface and cell deformation is numerically and experimentally investigated. As previous studies were mostly focused on the effect of electric fields on a group of cells, the present study focused on the behavior of a single cell exposed to an electric field. To accomplish this, the effect of cells on electrostatic potential distribution and electric field must be considered. To do this, Fast immersed interface method (IIM) was used to discretize the governing quasi-electrostatic equations. Numerical results confirmed the accuracy of fast IIM in satisfying the internal electrical boundary conditions on the cell surface. Finally, experimental results showed the effect of applied electric field on cell deformation at different frequencies.

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Insulator-based dielectrophoresis is a recently developed technique in which insulating posts are used to produce non-uniformity in the electric eld in a microchannel. This study presents the e ects of insulating posts' geometry and arrangement on the trapping e ciency of red blood cells in an alternating current-insulator-based dielectrophoresis system. Microchannels containing square, circular, and diamond-shaped posts with particles under the in uence of positive dielectrophoresis force and uid ow were considered in this study. The nite element method was used to compute the velocity of the ow and electric eld. The numerical method was veri ed by comparing the numerical results with experimental data. Two distinct criteria for examining particle trapping for distinct shapes and arrangements of insulating posts were introduced. Particle tracing simulation was implemented to observe particle trapping and compare the trapping performance of systems with distinct posts. As shown in the results for the system with circular and square posts, insulators should be narrowed to improve particle trapping, while the diamond post should be widened to increase the trapping e ciency. In addition, the particle tracking results showed that the microchannel with square posts was more e cient in particle trapping.

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