Dielectrophoresis and COMSOL simulation of cell entrapment at electrodes

Dielectric properties of biological samples change with frequency of the interrogating electric field therefore frequency dependent response can be used to obtain information about structures as well as various kinetic, biophysical and chemical processes in the cells. We analyzed cells by impedance and capacitance/conductance measurements after trapping them directly on miniaturized electrodes using dielectrophoresis (DEP). The electrode structures with cells attached at their edges, as obtained experimentally, were simulated using Comsol Multiphysics 3.4. Dielectric behavior of the system under ac voltages of different frequencies was studied. Mathematical modeling was done. Both in design/fabrication of the structures and in simulations we took into account the polarization effect at the electrode/electrolyte interface, which at low frequency range introduces very significant errors.