The innovations in the field of microelectrodes for biological applications have been significant advances in fabrication of the same for the recording and stimulus the excitable tissue (skin, muscle, neurons), for  invasive or noninvasive methods, that help in the control of the motor movement, formation of the memory, rehabilitation and the monitoring of the neuronal activity. In particular these microelectrodes have been fabricated on a variety of substrates such as; silicon, metals and recently polymers, which must fulfill certain specifications of biocompatibility like, electrical, geometric and chemical. That way in this work studies the case of the current density distribution generated and impedance into finite element of alternative materials for microelectrode implementation. Examines the effects that the microelectrode electrolyte interface, of geometries of the microelectrodes submerged in physiological saline, as well as the electrical impedance, which is critical in the recording and neuronal stimulation. These effects will be examined by finite element method of through ANSYS^®. The results obtained by uniform electric fields of variable frequency, will give to the information of the behavior of the current density distribution generated and the electrical impedance in the microelectrode electrolyte interface. In the future this information will serve for the implementation of a recording system of the neuronal activity.