Nitrogen‐Doped Multilayer Graphene Microtubes for High‐Density Recording of Occipital EEG Signals

Abstract Graphene microelectrodes exhibit potential in recording high‐density electroencephalography (EEG) signals from various brain regions. In this study, microtubes composed of nitrogen‐doped graphene (NG) nanosheets are synthesized by chemical vapor deposition to record high‐density EEG signals. The N‐content of the NG samples ranges from 1.35 to 2.22 at.%. One of the fabricated microtubes with an N‐content of 2.22% exhibits low scalp‐contact resistance and high signal‐to‐noise ratio (SNR) of EEG signals. The NG‐microtube has the advantages of high water‐retention, scalp affinity, water absorption, salt interception, and low resistance; these advantages reduce the scalp‐contact resistance and improve the response of EEG signals. Furthermore, an occipital 24‐lead EEG sensor with 72 optimized NG microtubes is assembled to record spontaneous and visually evoked EEG signals. Untrained volunteers are asked to wear the NG‐EEG sensor, and thus, spontaneous EEG with a high SNR and visually evoked EEG signals with an interval of 0.1 Hz are obtained easily. The occipital NG‐based EEG sensor is convenient to wear and can identify high‐density EEG signals. Therefore, the EEG sensor is not only suitable for the peripheral fine control of motion imagination but also used in the clinical diagnosis of functional disorders in various brain regions, promoting the development of healthcare electronics.