Development of Human-Scale Dry EEG based on 2D MXene and Benchmarking Against Clinical Gelled Electrodes

Electroencephalography (EEG) is a valuable tool for non-invasive monitoring of electrical activity from the scalp for clinical monitoring of neurological disorders. Clinical EEG typically involves gel-based electrodes, whose application is time-consuming and requires skin-irritating abrasives and pastes. Recently, we have introduced dry EEG electrodes based on Ti₃C₂MXene materials. These electrodes offer enhanced comfort and ease of use, requiring minimal skin preparation. Furthermore, they are conformable to the scalp, providing a comfortable fit for users. Here, we advance this technology towards research and clinical use by fabricating two different configurations of EEG headsets. The first configuration is a reduced-montage headband consisting of 8 channels placed at equal spacing on FP1, FP2, F7, F8, T3, T4, T5. The second configuration is a standard 10-20 montage with 21 recording sites at the canonical scalp locations. In both devices, the dry electrodes are fabricated from porous pillars infiltrated with Ti₃C₂MXene (diameter: 8 mm, height: 6 mm), enabling access to the scalp through hair without the need for gel or pastes. The electrodes are connected to the recording amplifiers via snap connectors attached to snap leads. Owing to the high electrical conductivity (155 ± 4 Ω, n= 5 electrodes) and surface area, the average 10 Hz impedance with the scalp of these dry porous MXene-infused electrodes is 2.1 ± 1.8 kΩ (n=5 subjects). To further validate the dry MXene EEG technology, we have benchmarked it against clinical gelled cup Natus electrodes. Briefly, we have recruited patients in the outpatient epilepsy clinic at the Hospital of the University of Pennsylvania. For each participant, we recorded EEG with the reduced-montage headset and MXene electrodes for 20 minutes prior to clinical EEG. We recorded EEG in the following conditions: resting state, eyes open/closed, and sleeping, which corresponded to the same tasks used during clinical EEG acquisition. A preliminary analysis of the recordings shows comparable quality of the EEG signals acquired with the dry MXene and clinical gelled electrodes, while the duration of the skin prep and electrode placement operation reduced by ~2X. In conclusion, we have developed and validated a novel dry EEG technology that can improve user comfort, reduce electrode placement and skin preparation time, and reliably transmit signals of interest, providing a comfortable and efficient solution for EEG monitoring.