Transdermal drug-delivery motion-sensing hydrogels for movement recovery caused by external injury

External injuries that restrict movement require hydrogel sensors capable of delivering drugs to the corresponding skin for therapy and concurrently motion monitoring to assist in restoring motor function. In this study, we incorporated gallic acid (GA)-Fe 3+ –H 2 O 2 Fenton-like dynamic redox autocatalysis into hydrogels to generate significant quantities of hydroxyl radicals and accelerate gelation times (to seconds). The synthesized GA-Fe 3+ / polyacrylic acid (PAA) hydrogels possess copious hydrogen and metal-coordination bonds due to the incorporation of GA and Fe 3+ , imparting self-healing capabilities and antibacterial properties in addition to a maximum tensile strength of 50.37 kPa, a self-adhesive strength of 17.53 kPa, 100 % UV resistance, and a conductivity of 1.401 S m −1 . Hydrogels employed in wearable-sensing application exhibit high sensitivities, repeatabilities, and rapid response properties, enabling precise monitoring of human movement. Additionally, drug-loaded hydrogels exhibited up to 22.31 % drug release during 1 h of transdermal drug delivery. A significant reduction in drug release during transdermal experiments with drug-loaded hydrogels following motion stretching indicates that the drug had been successfully released during tensile sensing testing. Consequently, this autocatalytic system presents promising prospects for developing hydrogels suitable to transdermal drug-delivery motion-sensing for movement recovery caused by external injury.