Wafer-scale fabrication of penetrating neural microelectrode arrays
The success achieved with implantable neural interfaces has motivated the development of novel architectures of electrode arrays and the improvement of device performance. The Utah electrode array (UEA) is one example of such a device. The unique architecture of the UEA enables single-unit recording with high spatial and temporal resolution. Although the UEA has been commercialized and been used extensively in neuroscience and clinical research, the current processes used to fabricate UEA’s impose limitations in the tolerances of the electrode array geometry. Further, existing fabrication costs have led to the need to develop less costly but higher precision batch fabrication processes. This paper presents a wafer-scale fabrication method for the UEA that enables both lower costs and faster production. More importantly, the wafer-scale fabrication significantly improves the quality and tolerances of the electrode array and allow better controllability in the electrode geometry. A comparison between the geometrical and electrical characteristics of the wafer-scale and conventional array-scale processed UEA’s is presented.
KeywordsUtah electrode array (UEA) Neural interface MEMS High aspect ratio Wafer-scale fabrication Microelectrodes
- R. Bhandari, S. Negi, L. Rieth, F. Solzbacher, “A Wafer Scale Etching Technique for High Aspect Ratio Implantable MEMS Structures,” accepted in Sensors and Actuators Phys (2010)Google Scholar
- R. Bhandari, S. Negi, L. Rieth, R.A Normann, F. Solzbacher, A novel masking technique for high aspect ratio penetrating microelectrode arrays. Journal of Micromechanics and Microengineering, doi:10.1088/0960-1317/19/3/035004, 2009.
- R. Bhandari, S. Negi, L. Rieth, F. Solzbacher. Wafer-scale processed, low impedance, neural arrays with varying length microelectrodes. in Proceedings of Transducers ’09, Denver, USA, June 21–25, 2009.Google Scholar
- A. Branner, R.B. Stein, R.A. Normann, Selective stimulation of cat sciatic nerve using an array of varying-length microelectrodes. J Neurophysiol 85, 1585–94 (2001)Google Scholar
- J.-M. Hsu, S. Kammer, E. Jung, L. Rieth, R.A. Normann, F. Solzbacher, Characterization of parylene-C film as an encapsulation material for neural interface devices (Borovets, Bulgaria, 2007). presented at 4M2007 Conference on Multi-Material Micro ManufactureGoogle Scholar
- J.-M. Hsu, L. Rieth, R.A. Normann, P. Tathireddy, F. Solzbacher, Encapsulation of an integrated neural interface device with parylene-C. IEEE Trans. Biomed. Eng. 55, 1–7 (2008)Google Scholar
- S. Kim, R. Bhandari, M. Klein, S. Negi, L. Rieth, P. Tathireddy, M. Toepper, H. Oppermann, F. Solzbacher, Integrated Wireless Neural Interface Based on the Utah Electrode Array. Biomedical Microdevices, doi: 10.1007/s10544-008-9251-y, (2008)
- S. Musallam, M.J. Bak, P.R. Troyk, R.A. Andersen, A floating metal microelectrode array for chronic implantation. J Neurosci 160, 122–127 (2007)Google Scholar
- S. Negi, R. Bhandari, L. Rieth, and F. Solzbacher. Effect of sputtering pressure on pulsed-DC sputtered iridium oxide films for neuroprosthetic applications. Sensors & Actuators B Chem, doi:10.1016/j.snb.2008.11.015, (2008)