Inkjet Printed Neural Electrode Arrays

Abstract

Technology for studying the brain is crucial for advancing our understanding of the nervous system and developing better treatments for the disorders that affect it. Electrophysiological and optical methods are powerful tools used to study the mechanisms of neural dynamics, and interfaces which combine these methods for multimodal experiments are a crucial step in the progression of technology for neuroscience applications. For this reason, transparent electrocorticography (ECoG) electrode arrays are important devices for facilitating such multimodal experiments. However, previous realizations of transparent ECoG arrays have depended on vapor deposition and photolithographic processes, preventing them from being produced at low cost, and limiting the ability to reconfigure electrode layouts for custom applications.Here we take advantage of inkjet printing to pattern the transparent conductor PEDOT:PSS to create transparent ECoG electrode arrays. These devices provide high optical transmittance while offering excellent impedance and charge injection properties. We integrate these electrode arrays into chronically-implantable, large-area cranial windows which provide a high quality multimodal neural interface for over 100 days in mice. We utilize these devices, which we call `eSee-Shells' to perform a variety of multimodal experiments, demonstrating their utility \textit{in vivo} for either recording ECoG or delivering electrical stimulation to the mouse cortex with simultaneous calcium imaging.