Self‐Reinforced Hydrogel‐Based Skin‐Contactable Flexible Electronics for Multimodal Electrophysiological Signal Monitoring and Emergency Alarming System

Abstract Inherently tissue‐like feature and multifunctional property of hydrogels make themself excellent materials for flexible electronics. However, conventional hydrogels with insufficient mechanical strength and poor fatigue resistance are damaged or lose service stability when subjected to alternating stress. Herein, self‐reinforced hydrogels are fabricated from elaborately designed ionic conductive hydrogels after repetitive sweat soak‐dehydration (SSD) treatment. The tensile strength of self‐reinforced hydrogels is improved to 930 from 480 kPa and exhibits insensitivity to crack propagation in any direction after 6 SSD treatment cycles. In addition, the self‐reinforced hydrogels show excellent skin friendliness compared with commercial wearable materials in a skin‐compatibility mouse model. Bringing together those advantages, various skin‐contactable flexible electronics are fabricated utilizing the self‐reinforced hydrogels and an emergency alarming system for acute myocardial infarction caused cardiogenic shock is also integrated that is expected to help potential patients in accidents.