Flexible MicroLED–electrocorticography sheet for wide-area bidirectional neural interface in mice

We demonstrate a flexible bidirectional neural interface integrating 16 InGaN-based MicroLEDs and 32 ECoG electrodes on a parylene C substrate via low-temperature indium bonding at 160 °C that slides epidurally from the parietal surface to the deep lateral cortex in mice without brain penetration. This is the first sheet-type device to achieve wide-area-optogenetic stimulation and -electrophysiological recording beyond the limitation only for the dorsal cortex in a rodent’s brain. In vivo experiments confirm simultaneous access to four sensory cortices through sensory-evoked responses and demonstrate optogenetic neural activation absent in a wild-type control.