Durability of high surface area platinum deposits on microelectrode arrays for acute neural recordings
- 558 Downloads
The durability of high surface area platinum electrodes during acute intracerebral measurements was investigated. Electrode sites with extremely rough surfaces were realized using electrochemical deposition of platinum onto silicon-based microelectrode arrays from a lead-free platinizing solution. The close to 1000-fold increase in effective surface area lowered impedance, its absolute value at 1 kHz became about 7 and 18 % of the original Pt electrodes in vitro and in vivo, respectively. 24-channel probes were subjected to 12 recording sessions, during which they were implanted into the cerebrum of rats. Our results showed that although on the average the effective surface area of the platinized sites decreased, it remained more than two orders of magnitude higher than the average effective surface area of the original, sputtered thin-film platinum electrodes. Sites with electrochemical deposits proved to be superior, e.g. they provided less thermal and 50 Hz noise, even after 12 penetrations into the intact rat brain.
KeywordsPCBs Electrochemical Impedance Spectroscopy Electrode Impedance Effective Surface Area Microelectrode Array
Useful and motivating discussions with Dr. Tamás Pajkossy are greatly acknowledged. We are grateful to Mrs. Károlyné Payer, Mr. András Strasszner, Mr. Róbert Hodován and Mr. András Lőrincz for their support in the clean room. We also wish to thank Mr. Attila Nagy and Mr. István Réti for their help in chip packaging, also to Mr. Péter Kottra and Mr. István Wosinski for their support in the in vivo experiments. Anita Pongrácz is thankful for the Bolyai János Grant of the HAS. This research was supported by the Hungarian Science Foundation (OTKA K81354), the French-Hungarian ANR-TÉT Neurogen, ANR-TÉT Multisca, TAMOP-4.2.1.B-11/2/KMR-2011-0002 and EU FP7 600925 Neuroseeker grants to István Ulbert.
- 2.Najafi K, Wise K. Implantable multielectrode array with on-chip signal processing, solid-state circuits conference digest of technical papers. IEEE International. 1986;1986:98–9.Google Scholar
- 3.Neves H. Advances in cerebral probing using modular multifunctional probe arrays. Med Device Technol. 2007;18:38–9.Google Scholar
- 10.Du J, Blanche TJ, Harrison RR, Lester HA, Masmanidis SC. Multiplexed, high density electrophysiology with nanofabricated neural probes. PLoS One. 2011;6:12.Google Scholar
- 29.Desai SA, Rolston JD, Guo L, Potter SM. Improving impedance of implantable microwire multi-electrode arrays by ultrasonic electroplating of durable platinum black. Front Neuroeng. 2010;3:00005.Google Scholar
- 36.G. Marton, Z. Fekete, I. Bakos, G. Battistig, A. Pongracz, P. Baracskay, et al., Deep-brain silicon multielectrodes with surface-modified Pt recording sites, Sensors, 2012. IEEE 2012;1–4.Google Scholar
- 37.Woods R. Chemisorption at electrodes: hydrogen and oxygen on noble metals and their alloys. In: Bard AJ, editor. Electroanalytical chemistry: a series of advances. New York: Dekker; 1976.Google Scholar
- 38.Paxinos G, Watson C. The rat brain in stereotaxic coordinates. 6th ed. San Diego: Academic Press; 2009.Google Scholar
- 47.Nicholson C, Phillips JM. Ion diffusion modified by tortuosity and volume fraction in the extracellular microenvironment of the rat cerebellum. J Physiol. 1981;321:225–57.Google Scholar
- 48.J.A. Latikka, J.A. Hyttinen, T.A. Kuurne, H.J. Eskola, J.A. Malmivuo, The conductivity of brain tissues: comparison of results in vivo and in vitro measurements, Engineering in Medicine and Biology Society, 2001. Proceedings of the 23rd Annual International Conference of the IEEE 2001, vol. 1, pp. 910–2.Google Scholar
- 49.Fontanini A, Spano P, Bower JM. Ketamine-xylazine-induced slow (<1.5 Hz) oscillations in the rat piriform (olfactory) cortex are functionally correlated with respiration. J Neurosci. 2003;23:7993–8001.Google Scholar