In vitro study of iridium electrodes for neural stimulation.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference (2013-02-01)
Naser Pour Aryan, Christian Brendler, Viola Rieger, Sebastian Schleehauf, Gerhard Heusel, Albrecht Rothermel
ABSTRACT

Iridium is one of the main electrode materials for applications like neural stimulation. Iridium has a higher charge injection capacity when activated and transformed into AIROF (activated iridium oxide film) using specific electrical signals. Activation is not possible in stimulating devices, if they do not include the necessary circuitry for activation. We introduce a method for iridium electrode activation requiring minimum additional on-chip hardware. In the main part, the lifetime behavior of iridium electrodes is investigated. These results may be interesting for applications not including on-chip activation hardware, and also because activation has drawbacks such as worse mechanical properties and reproducibility of AIROF.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Iridium, powder, 99.9% trace metals basis
Sigma-Aldrich
Iridium, wire, diam. 0.15 mm, 99.9% trace metals basis
Sigma-Aldrich
Iridium, evaporation slug, diam. × L 0.6 cm × 1.2 cm, 99.9% trace metals basis
Sigma-Aldrich
Iridium, black, powder, −200 mesh, ≥99% trace metals basis
Sigma-Aldrich
Iridium, foil, thickness 0.25 mm, 99.9% trace metals basis