Pillar-shaped stimulus electrode array for high-efficiency stimulation of fully implantable epiretinal prosthesis
| Autor: | Tetsu Tanaka, Mitsumasa Koyanagi, Takafumi Fukushima, Yoshinobu Watanabe, Kang-Wook Lee, Chikashi Kigure |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Passivation business.industry Mechanical Engineering Pillar Multielectrode array Electronic Optical and Magnetic Materials Surface tension Mechanics of Materials Electrode Electrode array Optoelectronics Electrical and Electronic Engineering business Electrical impedance Polyimide Biomedical engineering |
| Zdroj: | Journal of Micromechanics and Microengineering. 22:105015 |
| ISSN: | 1361-6439 0960-1317 |
| DOI: | 10.1088/0960-1317/22/10/105015 |
| Popis: | We developed a pillar-shaped microelectrode array (MEA) with varying heights for enhancing the spherical conformity of fully implantable epiretinal prosthesis comprising a 3D stacked retinal chip. The fabricated MEA is composed of 100 pillar electrodes with heights ranging from 60 to 80 µm. The Pt-coated Cu pillar electrode with a surface diameter of 70 µm and a height of 75 µm and the Pt planar electrode with a surface diameter of 70 µm have 24.6 and 125 kΩ impedances, respectively, at 1 kHz in vitro experiment. The pillar electrode shows lower impedance than the planar electrode because of a larger surface area. However, to avoid cross-talking between pillar electrodes, we developed a sidewall passivation process of the pillar electrode by using the surface tension of polyimide. The impedance of the isolated pillar electrode 116 kΩ at 1 kHz is similar to the impedance of the planar electrode, because they have similar electrode surface areas. The pillar-shaped MEA shows a better spherical conformity. |
| Databáze: | OpenAIRE |
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