Abstract
In neuroprosthetic applications, long-term electrode viability is necessary for robust recording of the activity of neural populations used for generating communication and control signals. The corrosion of tungsten microwire electrodes used for intracortical recording applications was analyzed in a controlled bench-top study and compared to the corrosion of tungsten microwires used in an in vivo study. Two electrolytes were investigated for the bench-top electrochemical analysis: 0.9% phosphate buffered saline (PBS) and 0.9% PBS containing 30mM of hydrogen peroxide. The oxidation and reduction reactions responsible for corrosion were found by measurement of the open circuit potential and analysis of Pourbaix diagrams. Dissolution of tungsten to form the tungstic ion was found to be the corrosion mechanism. The corrosion rate was estimated from the polarization resistance, which was extrapolated from the electrochemical impedance spectroscopy data. The results show that tungsten microwires in an electrolyte of PBS have a corrosion rate of 300-700μm/yr. The corrosion rate for tungsten microwires in an electrolyte containing PBS and 30mM H2O2 is accelerated to 10,000-20,000μm/yr. The corrosion rate was found to be controlled by the concentration of the reacting species in the cathodic reaction (e.g. O2 and H2O2). The in vivo corrosion rate, averaged over the duration of implantation, was estimated to be 100μm/yr. The reduced in vivo corrosion rate as compared to the bench-top rate is attributed to decreased rate of oxygen diffusion caused by the presence of a biological film and a reduced concentration of available oxygen in the brain.
| Original language | English |
|---|---|
| Pages (from-to) | 158-171 |
| Number of pages | 14 |
| Journal | Journal of Neuroscience Methods |
| Volume | 198 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 15 2011 |
Fingerprint
Keywords
- Neural recording electrode
- Tungsten corrosion
- Tungsten microwire array
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Corrosion of tungsten microelectrodes used in neural recording applications. / Patrick, Erin; Orazem, Mark E.; Sanchez, Justin C.; Nishida, Toshikazu.
In: Journal of Neuroscience Methods, Vol. 198, No. 2, 15.06.2011, p. 158-171.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Corrosion of tungsten microelectrodes used in neural recording applications
AU - Patrick, Erin
AU - Orazem, Mark E.
AU - Sanchez, Justin C.
AU - Nishida, Toshikazu
PY - 2011/6/15
Y1 - 2011/6/15
N2 - In neuroprosthetic applications, long-term electrode viability is necessary for robust recording of the activity of neural populations used for generating communication and control signals. The corrosion of tungsten microwire electrodes used for intracortical recording applications was analyzed in a controlled bench-top study and compared to the corrosion of tungsten microwires used in an in vivo study. Two electrolytes were investigated for the bench-top electrochemical analysis: 0.9% phosphate buffered saline (PBS) and 0.9% PBS containing 30mM of hydrogen peroxide. The oxidation and reduction reactions responsible for corrosion were found by measurement of the open circuit potential and analysis of Pourbaix diagrams. Dissolution of tungsten to form the tungstic ion was found to be the corrosion mechanism. The corrosion rate was estimated from the polarization resistance, which was extrapolated from the electrochemical impedance spectroscopy data. The results show that tungsten microwires in an electrolyte of PBS have a corrosion rate of 300-700μm/yr. The corrosion rate for tungsten microwires in an electrolyte containing PBS and 30mM H2O2 is accelerated to 10,000-20,000μm/yr. The corrosion rate was found to be controlled by the concentration of the reacting species in the cathodic reaction (e.g. O2 and H2O2). The in vivo corrosion rate, averaged over the duration of implantation, was estimated to be 100μm/yr. The reduced in vivo corrosion rate as compared to the bench-top rate is attributed to decreased rate of oxygen diffusion caused by the presence of a biological film and a reduced concentration of available oxygen in the brain.
AB - In neuroprosthetic applications, long-term electrode viability is necessary for robust recording of the activity of neural populations used for generating communication and control signals. The corrosion of tungsten microwire electrodes used for intracortical recording applications was analyzed in a controlled bench-top study and compared to the corrosion of tungsten microwires used in an in vivo study. Two electrolytes were investigated for the bench-top electrochemical analysis: 0.9% phosphate buffered saline (PBS) and 0.9% PBS containing 30mM of hydrogen peroxide. The oxidation and reduction reactions responsible for corrosion were found by measurement of the open circuit potential and analysis of Pourbaix diagrams. Dissolution of tungsten to form the tungstic ion was found to be the corrosion mechanism. The corrosion rate was estimated from the polarization resistance, which was extrapolated from the electrochemical impedance spectroscopy data. The results show that tungsten microwires in an electrolyte of PBS have a corrosion rate of 300-700μm/yr. The corrosion rate for tungsten microwires in an electrolyte containing PBS and 30mM H2O2 is accelerated to 10,000-20,000μm/yr. The corrosion rate was found to be controlled by the concentration of the reacting species in the cathodic reaction (e.g. O2 and H2O2). The in vivo corrosion rate, averaged over the duration of implantation, was estimated to be 100μm/yr. The reduced in vivo corrosion rate as compared to the bench-top rate is attributed to decreased rate of oxygen diffusion caused by the presence of a biological film and a reduced concentration of available oxygen in the brain.
KW - Neural recording electrode
KW - Tungsten corrosion
KW - Tungsten microwire array
UR - http://www.scopus.com/inward/record.url?scp=79957713858&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79957713858&partnerID=8YFLogxK
U2 - 10.1016/j.jneumeth.2011.03.012
DO - 10.1016/j.jneumeth.2011.03.012
M3 - Article
VL - 198
SP - 158
EP - 171
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
SN - 0165-0270
IS - 2
ER -