Out-of-plane neural microelectrode arrays fabrication using conventional blade dicing

• Main Authors: Oliveira, M. J. (Author), Peixoto, A. C. (Author), Correia, J. H. (Author), Goncalves, S. B (Contributor), Silva, A. F. (Contributor)
• Other Authors: MIT-Portugal Program (Contributor)
• Format: Article
• Language: English
• Published: Springer London, 2017-02-02T19:51:21Z.
• Subjects: Article
• Online Access: Get fulltext

 \This paper describes an optimized out-of-plane fabrication method for neural 3D high-aspect-ratio microelectrode array (MEA) based on a dicing technology platform (a standard procedure in semiconductor industry). The proposed MEA fabrication required important modifications in the dicing process. Since electrodes length reaches up to 4 mm, the main hindrance was the 2 mm cutting depth limit allowed for dicing machines with regular blades. This new procedure consisted on modifying Z-axis calibration, so cuts as deep as the exposure of blades were possible. The employment of proper blades for each fabrication step was also mandatory. Thin and high-exposure blades were used for deep cuts in silicon wafers, and V-shaped blades were employed to produce sharpened tips on the electrodes. Moreover, parameters as very low-cut speeds were essential to avoid wafer chipping and microcracks. Results showed high-precision and high-quality cuts in all steps of the 3D MEA fabrication, without unnecessary additional steps of etching post-processing. The optimized fabrication process was successfully demonstrated with a 3D neural probe array comprising 36 individually addressable electrodes.