3D-Printed, High-Adhesion, Porous, and BreathableHydrogel Patches for ECG Monitoring as Wearable Sensors

Hydrogels are widely used as bioelectrodes for human health monitoring owing to their flexibility and biocompatibility. However, most conventional hydrogels lack breathability, which hinders sweat evaporation, leading to skin irritation and compromised signal quality, thereby limiting their applicability in wearable sensors. Consequently, developing lightweight, comfortable, and stable sensors for long-term use remains challenging. Herein, we propose a conductive and adhesive porous hydrogel patch (denoted as PDA, standing for porous DAC-containing acrylic-based hydrogel) fabricated via digital light processing (DLP) 3D printing, which is further integrated with textiles to construct a fabric-based wearable bioelectrode (denoted as FPD, fabric-integrated PDA hydrogel). The PDA hydrogel exhibited skin-mimetic mechanical properties, with a tensile fracture strength of 54 kPa, a fracture elongation of 210%, and an elastic modulus of 36.3 kPa. Owing to the incorporation of a cationic monomer, the hydrogel demonstrated pronounced interfacial adhesion to diverse substrates, achieving an adhesion strength of up to 25.449 kPa on cotton fabric. Moreover, the printed open porous architecture markedly enhanced breathability, delivering a water vapor transmission rate (WVTR) of 1466.42 g·m^–2·day^–1, which was 10.18 times that of the nonporous hydrogel. Overall, this study establishes a synergistic “materials chemistry–structural design–textile integration” strategy, and the resulting fabric-based hydrogel sensor demonstrates strong feasibility for wearable devices, long-term motion monitoring, and continuous human health surveillance.