Gold nano-network transparent ECoG array for photoelectric artifact-free neural recording

Abstract

In order to investigate the mechanisms of brain disorders such as depression and Alzheimer’s disease and develop treatments for brain disorders, it is important to reveal the brain circuits. To identify the brain, researchers have measured electrophysiological signals in the brain by inserting an electrode into the brain. Recently, some researchers tried to integrate light-using techniques such as the optogenetics to control the activity of neurons by light and phototherapy to treat some diseases by light with brain signal measurement. However, when illuminating light on a typical metal electrode, it is difficult not only to transmit light due to its low transmittance, but also to measure accurate brain signals due to photoelectric artifact, which is occurred by Becquerel effect. Herein, a novel transparent microelectrode array based on the Au nano-network s tructure was proposed and developed. The nano-network based electrodes showed smaller photoelectric artifact attenuation effect over 10 times compared to the Au film electrode and enable to measure the accurate ECoG signals upon low powered optical stimulation. However, due to the difficulty to fabricate transparent electrodes which show low electrochemical impedances and high transmittance of 90% or more, the proposed electrodes cannot attenuate the photoelectric artifact completely.