(28q) 3D-Printed Implantable Neural Arrays Based on Templated Conductive Polymer Electrodes

Implantable neural arrays are promising bioelectronics for recording electrophysiological signals from brains with high precision. However, most neural arrays are limited in their configuration due to fabrication processes or material choices. These limitations hinder the development of the next-generation implantable bioelectronics. To overcome these challenges, we introduce 3D-printed neural arrays that can be configured to specific needs. Poly(3,4-ethylenedioxythiophene) doped with tetrafluoroborate (PEDOT:BF₄) is electrochemically deposited inside 3D-printed microchannels, growing vertically along the shape of the microchannels. These self-assembled PEDOT:BF₄ electrodes are electrochemically stable and have low interfacial impedance. Impedance measurements reveal a lower impedance of the PEDOT electrodes than conventional metal electrodes. The electrochemical stability of the PEDOT:BF₄ electrodes is confirmed by the cyclic voltammetry and is found to be constant without significant changes for successive cycles. These results indicate that the 3D-printed neural arrays based on templated PEDOT:BF₄ are a promising bioelectronic platform for intracortical recording of electrophysiological signals. Moreover, the numerous designs available through 3D printing offer opportunities to go beyond the current limitations of neural array configurations.