Flexible, Multi-Shank Stacked Array for High-Density Omini-Directional Intracortical Recording

This paper presents a flexible multi-shanks omini-directional neural probe array. The flexible probe includes eight shanks with different length, each shank contains 128 recording sites. Traditional Multilayer lithography is applied to fabricate the probe and a novel stacked structure is design with four-sided electrodes (32 sites on surface and 96 sites on sidewall) is proposed in this multi-shank array, which increases the electrode density of integration and the stacked structure can be readily scaled up to 1024 channels. It has been proved that the impedance at 1 kHz of the electrodes on the surface and the sidewalls are 830 kΩ and 1.1 MΩ in vitro respectively. With such design, longer life span can be achieved and the probe can capture richer neural signal. In addition, a method of microwire assisted implantation is proposed to ensure successful implantation in agar model.