Modular assembly of flexible thin-film electrode arrays enabled by a laser-structured ceramic adapter

摘要

The assembly of flexible polyimide-based thin-film electrode arrays with commercial Nano Omnetics connectors turned out to be a sensitive and very time-consuming fabrication step in the past, especially when high integration densities of connector pads had to be addressed. We developed a laser-structured ceramic adapter, which simplifies this assembly and which allows a robust and reliable connection between the connectors and the thin-film electrode arrays. Furthermore, the adapter facilitates the handling of the flexible devices and offers the possibility of a modular system design and assembly of the polyimide-based thin-film electrode arrays. An ECoG-array with 252 recording electrode sites has been chosen as first design example in this study. The system was sub-divided in six single arms, whose cables were stacked on each other. Thereby, the cable width of the whole device could be reduced dramatically to 1.35 mm. The modular assembly also increases the fabrication yield due to a separation of MEMS processing and assembly. In case of failure occurrence during the MEMS processing (e.g. shortcut or open connection) only a single subsystem of the ECoG array is affected, which can easily be replaced by another one. The possibility of subsystem replacement also opens up a simple and fast way to implement design variations.