title: Bias voltages at microelectrodes change neural interface properties in vivo.
abstract: Rejuvenation of iridium microelectrode sites, which involves applying a 1.5 V bias for 4 s, has been shown to reduce site impedances of chronically implanted microelectrode arrays. This study applied complex impedance spectroscopy measurements to an equivalent circuit model of the electrode-tissue interface. Rejuvenation was found to cause a transient increase in electrode conductivity through an IrO2 layer and a decrease in the surrounding extracellular resistance by 85 +/- 1% (n=73, t-test p < 0.001) and a decrease in the immediate site resistance by 44 +/- 7% (n=73, t-test p<0.001). These findings may be useful as an intervention strategy to prolong the lifetime of chronic microelectrode implants for neuroprostheses.
authors.affiliation: Department of Biomedical Engineering, University of Michigan, MI, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Johnson
authors.forename: K J
authors.initials: KJ
authors.lastname: Otto
authors.forename: J C
authors.initials: JC
authors.lastname: Williams
authors.forename: D R
authors.initials: DR
authors.lastname: Kipke