Dielectrophoretic effect of nonuniform electric fields on the protoplast cell

In recent decades the effects of magnetic and electric fields on living cells and organisms have gained the increased attention of researchers. In recent years, dielectrophoresis based microfluidics systems have been used to manipulate biological micro particles, such as red blood cells, white blood cells, platelets, cancer cells, bacteria, yeast, microorganisms, proteins, DNA, etc. So most previous researchers have studied particle trajectory under the application of electric field in order to better design of such micro devices. In the current study the effect of nonuniform electric field on a single cell is investigated. A neutral particle polarizes in the presence of electric field. It causes local change in electrostatic potential distribution and local nonuniformity in electric field. These changes are ignored in previous researches and effective dipole moment (EDM) approximation is applied to predict the DEP force exerted on cells. In the present research the effect of cell on electrostatic potential distribution and electric stresses acting on cell surface is studied. To this end, the cell shape and internal boundary conditions on cell surface must be considered in computational domain. To do this, Immersed Interface Method (IIM) which is a modified finite difference method is employed. Some numerical results are presented to show the good accuracy of mentioned numerical method. The electric stresses on cell surface are calculated by Maxwell Stress Tensor (MST). Also some results are presented to validate the numerical solution and investigate the accuracy of EDM approximation. Other electrokinetic effects such as electrophoresis and electro-osmosis are neglected in this study.