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.
Bibliographical noteFunding Information:
This work was supported by grants from the National Institutes of Health (NIH NIBIB 1R01EB009103-01 and NIH NIBIB 2R01EB000856-06) and the Defense Advanced Research Projects Agency (DARPA RCI N66001-12-C-4025, DARPA HIST N66001-11-1-4013). A.S. is supported by NIH NIBIB 1T32EB011434-01A1. D.-W.P. and S.M. are partly supported by ONR under grant N00014-09-1-0803. S.M. is supported by GERS Fellowship and Winslow Sargeant Fellowship.
© 2014 Macmillan Publishers Limited. All rights reserved.