MEMS-Technology for Large-Scale, Multichannel ECoG-Electrode Array Manufacturing

摘要

We present a micromachined ECoG (electrocor-ticogram )-electrode array which combines structures in the micrometer range with a total array area of approximately 60 mm by 35 mm. This enables the distribution of 252 electrodes over a complete hemisphere of a monkey's cortex. The arrayand the integrated cables are processed on wafer level and are made of a 10 urn thick polyimide foil which encloses a 300 nm thick sputtered platinum layer serving as electrodes and conductor paths. The electrode sites are 1 mm in diameter, the conductor paths have a pitch of 30 μm. 8 Omnetics connectors (NPD series, Omnetics Connector Corp., Minneapolis, MN. USA) are directly soldered to the foil to maintain a small assembly size which allows free movements of the animal between experimental sessions. The electrodes are characterized by electrochemical impedance spectroscopy. At 1 kHz the electrode impedances vary between 1.5 kΩ and 5 kΩ. The yield of functionable electrodes is 99.5 %.