Fig. 1: The neurorevive-FlexChip.

a Completed Packaging of NeuroRevive-FlexChip (scale bars: 1 mm). b Full View of NeuroRevive-FlexChip (scale bars: 1 mm), and detailed image of the tip of the mfMEA in the black circle (scale bars: 100 μm). c The NeuroRevive-FlexChip fabrication process: i Deposition of a 6 μm parylene layer onto a cleaned silicon wafer; ii Spin-coating of photoresist AZ5214 onto the parylene layer; iii Photolithographic definition of patterns for the deep conductive layer; iv–v Sputtering and lift-off of the deep Cr/Au (30/200 nm) conductive layer; vi Deposition of a 2 μm parylene layer; vii Photolithographic definition of patterns for the shallow conductive layer; viii Sputtering and lift-off of the shallow Cr/Au (30/200 nm) conductive layer; ix Deposition of another 2 μm parylene layer; x Spin-coating of photoresist AZ4620 onto the parylene layer; xi–xii Exposure of microelectrodes and pads through photolithography and etching; xiii Spin-coating of photoresist AZ4903 onto the parylene layer; xiv–xv Patterning of the NeuroRevive-FlexChip contours through photolithography and etching. d Surface Potential Simulation from Electrical Stimulation (ES) (scale bars: 1 mm). e The electrochemical response under in vitro stimulation.