HE use of diamond for neural stimulation has been of interest, as the mechanical, chemical and biological stability of the material are advantageous All coatings were applied to a semi-spherical monopolar Ti6Al4V substrate (surface area: 0.06 cm 2 ). The TiN coatings were deposited using magnetron sputtering and had a thickness of ~4 µm. B-NCD was grown using a pulsed microwave plasma enhanced chemical vapor deposition apparatus with linear antenna delivery system [3] operating at low pressures with a CH 4 -H 2 -CO 2 chemistry with trimethylboron (TMB) as a boron dopant. Electrochemical measurements on three B-NCD electrodes were compared to measurements on a smooth and a porous TiN electrode. Measurements were performed in phosphate buffered saline (PBS) at room temperature. EIS was performed using Solartron, Model 1294 in conjunction with 1260 Impedance/gain-phase Analyzer (Solartron Analytical, UK). The impedance spectrum was measured from 0.1 Hz ± 100 kHz using a current of 5.0 µA. The electrolyte resistance was subtracted from the measured impedance. Voltage transient measurements (VTM) and cyclic voltammetry (CV) were performed using a VersaSTAT 3 potentio-galvanostat (Princeton applied research, USA). The water window potentials were established for the B-NCD electrodes, after which CV measurements were made at sweep rates of 0.05, 0.1, 0.5 and 1.0 V/s. For TiN -0.6 and 0.9 V vs. Ag|AgCl were used as water window potentials. The CSC c was computed at 0.05 V/
