Electrochimica Acta, Vol.56, No.17, 6001-6007, 2011
Effect of film structure on the electrochemical properties of gold electrodes for neural implants
The development of interfaces with low impedance is a prerequisite for long-term neural devices. A broad range of new materials has been developed for this purpose. Here we show how the performance of traditional gold electrodes can be improved by controlling the deposition parameters of the gold film. The morphology of the film was tuned from granular to columnar structure as shown by scanning electron microscopy of film cross sections. Electrochemical characterisation with impedance spectroscopy, chronoamperometry and cyclic voltammetry demonstrates that the dense columnar structure of the films effectively lowers the impedance of the interface and increases charge injection properties. The samples produced are also compared to titanium nitride films, a well-established electrode material with a columnar structure. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Neural electrodes;Gold;Thin film microstructure;Electrochemical characterisation;Titanium nitride