Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications

TLDR

Transparent neural micro‑electrode arrays spanning UV to IR enable simultaneous electrophysiology, optical imaging, and optogenetic modulation while long‑term biocompatibility demands mechanical flexibility and tissue compliance. The authors introduce a graphene‑based, carbon‑layered electrode array (CLEAR) that can be implanted on the rodent brain surface for high‑resolution neurophysiological recording. CLEAR achieves >90 % optical transmission across the UV–IR spectrum and is validated through optical interface experiments demonstrating its broad‑spectrum transparency. The device enables optogenetic activation of cortical regions beneath electrodes, in‑vivo imaging of cortical vasculature via fluorescence microscopy and 3‑D OCT, and overall demonstrates versatile interfacing capabilities for neural applications.

Abstract

Abstract Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications.