Water‐Resistant Ionogel Electrode with Tailorable Mechanical Properties for Aquatic Ambulatory Physiological Signal Monitoring

Abstract

Underwater electrocardiography (ECG) monitoring, which can monitor cardiac autonomic changes and arrhythmias during diving, is essential for sports management and healthcare. However, it is crucial yet rather challenging to achieve ECG monitoring in an aquatic environment because the interface electrodes may lose their functionality underwater. Here, an ionogel with tailorable mechanical properties is prepared by a facile one-step polymerization and used as water-resistant electrode. The Young's modulus and strain at break of the ionogel can be modulated in the range of 0.22-337 MPa and 349 to >10 000%, respectively. The hydrophobic polymer networks inside the ionogel endow this ionogel with excellent stability, adhesion, and selfhealing ability underwater. The ionic conductivity imparted by the free ionic groups inside the ionogel allows the ionogel to detect and transmit physiological electrical signals. Compared with commercial gel electrodes, this ionogel electrode demonstrates better adhesion ability, conductivity, and stability underwater. The ionogel electrode can collect real-time ECG signals effectively both in the air and underwater, and the data can be used to warn users of the potential risk of a heart attack.

Multifunctionally wearable monitoring with gelatin hydrogel electronics of liquid metals

“…Electrocardiography (ECG) plays an important role in current medical testing. It can be used to assist in the detection of diseases, especially heart diseases 37 (Fig. 6a).…”

“…In addition, in order to verify that LMGE has the ability to monitor human secretions, following the example of Ma et al , 37 we simulated human sweating (here just putting the LMGE in a Petri dish and then dripping the corresponding reagents through a disposable dropper to form a closed path, Fig. S15, ESI†).…”

Highly Transparent, Self-Healing, and Self-Adhesive Double Network Hydrogel for Wearable Sensors

“…The adhesion photographs and adhesion strength of the hydrogels on other substrates were shown in Figures 5Bi-iii,C, respectively. This adhesion was attributed to the high polarity of the zwitterionic polymer in hydrogel (Asha et al, 2021;Yu and Wu, 2021). Both charged groups (cationic quaternary ammonium and anionic sulfonate) and polar groups (S=O) tend to interact with other charged or polar groups on the surface of most substrates via ion dipole and/ or dipole-dipole interactions, resulting in a strong interfacial bonding (Kim et al, 2021).…”

Design of Double‐Network Click‐Gels for Self‐Contained Underwater Adhesion and Energy‐Wise Applications in Floating Photovoltaics

“…[58][59][60] It is noted that recent applications of underwater adhesives mainly focus on repairing, sensing, and communication in aquatic environments. [1][2][3][4][5][61][62] To the best of our knowledge, no energy-related application has been developed based on state-of-the-art underwater adhesives.…”