Ultra-Low Cost, Facile Fabrication of Transparent Neural Electrode Array for Electrocorticography with Photoelectric Artifact-Free Optogenetics

Abstract

Transparent implantable devices have received significant attention in neuroscience and biomedical engineering by combining neural recording and optical modalities. Opaque, metal-based electrode arrays for electrophysiology block optical imaging and cause photoelectric artifacts, making them difficult to integrate with optogenetics. Here, a photoelectric artifact-free, highly conductive, and transparent poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrode array is introduced as promising neural implants. The technology which is developed in this work provides transparent neural interfaces through low-cost, ultra-facile method compared with other transparent materials being applied to implantable tools. The device exhibits superior optical, mechanical, and electrical characteristics to other studies, thanks to a simple ethylene glycol immersing process. The device performance is highlighted by comparing its light stimulation efficiency and photoelectric artifact extent with conventional thin gold electrodes both in vitro and in vivo. This platform can assemble transparent neural interfaces much more efficiently than any other material candidates and thus has many potential applications.