Modeling of Electric Field and Dielectrophoretic Force in a Parallel-plate Cell-separation Device with an Electrode Lid and Analytical Formulation Using Fourier Series

Dielectrophoresis (DEP) cell-separation technology is an effective means of separating rare cells. To develop highly efficient cell-separation devices, detailed analysis of the nonuniform electric field’s intensity distribution within the device is needed, as it affects separation performance. Here we analytically expressed the distributions of the electric field and DEP force in a parallel-plate cell-separation DEP device by employing electrostatic analysis through the Fourier series method. The solution was approximated by extrapolating a novel approximate equation as a boundary condition for the potential between adjacent fingers of interdigitated electrodes and changed the underlying differential equation into a solvable form. The distributions of the potential and electric fields obtained by the analytical solution were compared with those from numerical simulations using finite element method software to verify their accuracy. The results showed excellent agreement. Three-dimensional fluorescence imaging analysis used live non-tumorigenic human mammary (MCF10A) cells. The distribution of cell clusters adsorbed on the interdigitated electrodes was compared with the analytically obtained distribution of the DEP force, and the mechanism underlying cell adsorption on the electrode surface was discussed. Furthermore, parametric analysis using the width and spacing of these electrodes as variables revealed that spacing is crucial for determining DEP force. The results showed that, by optimizing cell-separation devices using interdigitated electrodes, adjusting electrode spacing significantly enhances device performance.