Elastic 3D Microelectrodes with Jellyfish-Like Microbumps and Grapping Strips as a Reliable Neural Interface

This work reports an elastic 3D microelectrode array with jellyfish-like microbumps and grapping strips for the first time. The soft silicone microbump wrapped by thin-film polyimide (PI) strips is formed by stress-free premolding and post injection molding. The elastic structure serves as a reliable neural interface to push the microelectrode sites closer to the dura mater for high-quality electrocorticogram (ECoG) recording. Besides, the elastic interface with sufficient mechanical strength can withstand the external pressure from overlay of dental cement or cranial window, thanks to its self-compression capability without debonding of grapping strips or electrochemical degradation. Thus, this bionic structure has advantages to reshape the traditional 2D electrodes to 3D for more durable neural recording, and avoid the unbuffered contact of the overlaid sealing cement or window to the underlying soft tissue.