A Gelatin-Based Hydrogel Electrode With High Moisturizing Ability for Wearable EEG Recording

Clinically, an excellent electrode is of great significance for obtaining high-fidelity electroencephalogram (EEG) signals, which is a valuable tool for diagnosing brain-related diseases and exploring human brain activity. However, traditional wet electrode encounters a natural drawback in moisturizing ability due to the lack of water-locking ability to the electrolyte, unsuitable for long-term EEG acquisition. Hence, we propose a gelatin-based ionic conductive hydrogel electrode with a high moisturizing ability for wearable EEG acquisition. The gelatin material, derived mainly from animal collagen, is highly biocompatible and user-friendly. The gelatin-based hydrogel electrode is easy to prepare, possesses strong moisturizing ability, and performs relatively stable interfacial contact impedance. Remarkably, the gelatin-based hydrogel electrode modified by glycerol can still work normally even after 60 days. Additionally, the gelatin-based hydrogel electrode exhibits a low potential drift ( $1.863 \mu $ Vmin $^{-{1}}$ ) and a low short-circuit noise level. This work can lead to a new era of wearable EEG acquisition and provide an effective strategy for the convenient preparation of highly moisturizing hydrogel electrodes.