Journal article

Electrochemical and biological performance of chronically stimulated conductive hydrogel electrodes

Ashley N Dalrymple, Ulises A Robles, Mario Huynh, Bryony A Nayagam, Rylie A Green, Laura A Poole-Warren, James B Fallon, Robert K Shepherd



OBJECTIVE: Evaluate electrochemical properties, biological response, and surface characterization of a conductive hydrogel (CH) coating following chronic in vivo stimulation. APPROACH: Coated CH or uncoated smooth platinum (Pt) electrode arrays were implanted into the cochlea of rats and stimulated over a 5 week period with more than 57 million biphasic current pulses. Electrochemical impedance spectroscopy (EIS), charge storage capacity (CSC), charge injection limit (CIL), and voltage transient (VT) impedance were measured on the bench before and after stimulation, and in vivo during the stimulation program. Electrically-evoked auditory brainstem responses were recorded to monitor neural fu..

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Awarded by NHMRC of the Australian Government

Funding Acknowledgements

This work was funded by the NHMRC of the Australian Government (APP1122055) and the Garnett Passe and Rodney Williams Memorial Foundation for which we are most grateful. The Bionics Institute acknowledges support of the Victorian Government through Operational Infrastructure Support Program. We thank Drs. A Thompson and T Hyakumara, C McGowan, and R Thomas and the electrode fabrication team from the Bionics Institute; the staff of EMSU, St Vincent's Hospital Melbourne for animal care; R Curtain and the SEM Facility at Bio21, University of Melbourne; and the Electron Microscope Unit (EMU) within the Mark Wainwright Analytical Centre (MWAC) at UNSW Sydney for their technical assistance.