Weiguang Wang, Guangyuan Xu, Kai Huang, Chuantian Ren, Yufeng Wu, Yiqian Zhou, Zekun Cheng, Shuling Zhang, Hongwei Li, Yang Chen, Yang Lu, Shibiao Xu, Yong Liu, Ming Lei, Hui Wu
Bioelectrical signals, especially electroencephalography (EEG) and electrocardiography (ECG), are indispensable for health assessment. However, achieving high-quality signal acquisition while ensuring long-term stability remains a significant challenge in the bioelectrical electrodes. Herein, a cholinium-based eutectogel (ChCl-egel) is reported for dynamic ECG and EEG monitoring. By utilizing hydrogen bonding of deep eutectic solvents (DESs) to modulate conductivity, the ChCl-egel realizes an ultra-low skin impedance (4.7 kΩ at 10 Hz) with reliable stability. Additionally, the ChCl-egel exhibits excellent conformal contact and biocompatibility. During ECG monitoring, the ChCl-egel offers an 8 dB improvement in signal-to-noise ratio (SNR) compared to commercial ECG electrodes (3 M, Red Dot) over 48-hour period, enabling dynamic record under high-intensity exercises. In an 18-hour steady-state visual evoked potential (SSVEP) experiment, it can match the scalp impedance of commercial gel and support longer record. With high-quality dynamic monitoring capability, the ChCl-egel provides a promising solution for long-term bioelectrical signal acquisition.