Phytic acid-stabilized Tough, conductive, and stable liquid metal/polyvinyl alcohol hydrogel for human wireless health monitoring

Liquid metal (LM)-based conductive hydrogels have attracted considerable attention in wearable technology due to their superior electrical conductivity and excellent biocompatibility. However, developing LM composite hydrogels that simultaneously achieve high sensitivity, long-term durability, and superior mechanical properties remains a challenge for meeting the demands of advanced wearable applications. In this study, we introduce phytic acid (PA), a naturally occurring small molecule, whose unique interfacial stabilization properties arise from the dual functionality of its phosphate groups: (i) the ability to form strong coordination bonds with metal surfaces, and (ii) the enhancement of the polymer network through multiple hydrogen bonds and electrostatic interactions, significantly improving the dispersion stability of LM within the hydrogel matrix. Based on this strategy, we successfully fabricated PLM x hydrogels with superior electrical conductivity (∼0.53 S m −1 ), exceptional toughness (∼9.7 MJ m −3 ), and remarkable durability (>11,000 cycles). The PLM x hydrogel exhibits outstanding sensitivity (gauge factor ∼8.1) and enables wireless dual-mode signal detection—precisely monitoring vigorous human motion and sensitively detecting subtle physiological signals. Notably, even under prolonged use and high-frequency cycling conditions, the PLM x hydrogel maintains excellent signal responsiveness and operational stability, demonstrating its tremendous potential for applications in smart health monitoring, human-machine interfaces, and next-generation wearable devices.