10.3389/fbioe.2018.00171.s001
Suzan Meijs
Suzan
Meijs
Matthew McDonald
Matthew
McDonald
Søren Sørensen
Søren
Sørensen
Kristian Rechendorff
Kristian
Rechendorff
Ladislav Fekete
Ladislav
Fekete
Ladislav Klimša
Ladislav
Klimša
Václav Petrák
Václav
Petrák
Nico Rijkhoff
Nico
Rijkhoff
Andrew Taylor
Andrew
Taylor
Miloš Nesládek
Miloš
Nesládek
Cristian P. Pennisi
Cristian P.
Pennisi
Presentation_1_Diamond/Porous Titanium Nitride Electrodes With Superior Electrochemical Performance for Neural Interfacing.pdf
Frontiers
2018
neural prosthesis
neural interfaces
implantable electrodes
electrical stimulation
boron-doped diamond
porous diamond
titanium nitride
electrochemistry
2018-11-15 04:06:06
Presentation
https://frontiersin.figshare.com/articles/presentation/Presentation_1_Diamond_Porous_Titanium_Nitride_Electrodes_With_Superior_Electrochemical_Performance_for_Neural_Interfacing_pdf/7344146
<p>Robust devices for chronic neural stimulation demand electrode materials which exhibit high charge injection (Q<sub>inj</sub>) capacity and long-term stability. Boron-doped diamond (BDD) electrodes have shown promise for neural stimulation applications, but their practical applications remain limited due to the poor charge transfer capability of diamond. In this work, we present an attractive approach to produce BDD electrodes with exceptionally high surface area using porous titanium nitride (TiN) as interlayer template. The TiN deposition parameters were systematically varied to fabricate a range of porous electrodes, which were subsequently coated by a BDD thin-film. The electrodes were investigated by surface analysis methods and electrochemical techniques before and after BDD deposition. Cyclic voltammetry (CV) measurements showed a wide potential window in saline solution (between −1.3 and 1.2 V vs. Ag/AgCl). Electrodes with the highest thickness and porosity exhibited the lowest impedance magnitude and a charge storage capacity (CSC) of 253 mC/cm<sup>2</sup>, which largely exceeds the values previously reported for porous BDD electrodes. Electrodes with relatively thinner and less porous coatings displayed the highest pulsing capacitances (C<sub>pulse</sub>), which would be more favorable for stimulation applications. Although BDD/TiN electrodes displayed a higher impedance magnitude and a lower C<sub>pulse</sub> as compared to the bare TiN electrodes, the wider potential window likely allows for higher Q<sub>inj</sub> without reaching unsafe potentials. The remarkable reduction in the impedance and improvement in the charge transfer capacity, together with the known properties of BDD films, makes this type of coating as an ideal candidate for development of reliable devices for chronic neural interfacing.</p>