A Self-Adhesive, Motion-Resistant Multifunctional Hydrogel Patch with Island-Bridge Design for Comprehensive Sleep...

Sudden cardiac death and health risks associated with abnormal sleep patterns highlight the urgent need for comprehensive, interference-resistant sleep monitoring technologies. Traditional polysomnography is constrained by complexity and discomfort, while existing flexible sensors often suffer from single-function limitations, signal coupling, and mechanical interference. Herein, we propose a multifunctional sensing patch inspired by the island-bridge structure to address these challenges. The patch integrates temperature sensors and electrocardiogram (ECG) electrodes on low-water hydrogel (islands) and strain sensors for respiratory monitoring on high-water hydrogel (bridges), all based on poly(acrylic acid) hydrogel to eliminate mechanical mismatch and prevent delamination. Low-water and high-water hydrogels are fabricated by regulating glycerol (Gly) and ethylene glycol (EG) ratios to tune water content, achieving strain insensitivity for temperature/ECG regions and strain sensitivity for respiratory detection. The unique material combinations endow the temperature sensor with high sensitivity (4.02 °C^-1); the ECG electrode reduces noise interference by over 30% compared to commercial electrodes; the strain sensor achieves a gauge factor (GF, 23.31). When applied to human sleep monitoring, the patch enables precise, synchronous capture of body temperature, ECG signals, and respiratory patterns under various physiological conditions. This work provides a strategy for developing high-reliability, multifunctional sleep monitoring devices.