A Gelatin-Based Hydrogel Electrode With High Moisturizing Ability for Wearable EEG Recording
Gencai Shen, Kunyu Zheng, Chunpeng Jiang, Shuihan Shao, Nan Zhao, Jingquan Liu
Abstract
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 ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.863 \mu $ </tex-math></inline-formula> Vmin <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula> ) 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.