Sodium carboxymethyl cellulose/polyvinyl alcohol/clove essential oil composite hydrogel with integrated antibacterial, antifreeze, and conductive properties as a wearable sensor for human motion monitoring.

Conductive hydrogels have emerged as promising materials for flexible wearable electronics; however, their facile fabrication remains challenging. This study presents an antifreeze, antibacterial, and conductive hydrogel constructed from biomacromolecules sodium carboxymethylcellulose (CMC-Na) and polyvinyl alcohol (PVA). The hydrogel was synthesized via a simple one-pot method in an ethylene glycol/water (EG/H₂O) binary solvent system, incorporating lithium chloride (LiCl) and clove essential oil (CEO), followed by a single freeze-thaw cycle. The synergistic framework of CMC-Na and PVA endowed the hydrogel with robust mechanical flexibility and structural integrity. LiCl integration achieved high ionic conductivity (6.94Sm-1), while EG imparted exceptional freezing resistance, maintaining flexibility and conductivity at -50 °C. CEO provided potent antibacterial activity against common pathogens, significantly mitigating bacterial contamination risks. Owing to its high strain sensitivity, fast response time (<200 ms), and environmental resilience, the hydrogel served as an effective wearable sensor for real-time monitoring of human joint movements, subtle physiological signals. This work establishes a CMC-Na/PVA -based multifunctional hydrogel design paradigm, offering a scalable strategy for next-generation smart wearable devices.