NeuroBus - Architecture for an Ultra-Flexible Neural Interface
Markus Sporer, Ioana-Georgiana Vasilaș, Ahmed Adžemović, Nicolas Graber, Stefan Reich, Calogero Gueli, Max Eickenscheidt, Ilka Diester, Thomas Stieglitz, Maurits Ortmanns
Abstract
This article presents the system architecture for an implant concept called NeuroBus. Tiny distributed direct digitizing neural recorder ASICs on an ultra-flexible polyimide substrate are connected in a bus-like structure, allowing short connections between electrode and recording front-end with low wiring effort and high customizability. The small size (344 μm × 294 μm) of the ASICs and the ultraflexible substrate allow a low bending stiffness, enabling the implant to adapt to the curvature of the brain and achieving high structural biocompatibility. We introduce the architecture, the integrated building blocks, and the post-CMOS processes required to realize a NeuroBus, and we characterize the prototyped direct digitizing neural recorder front-end as well as polyimide-based ECoG brain interface. A rodent animal model is further used to validate the joint capability of the recording front-end and thin-film electrode array.