Vinyltrimethoxysilane-Functionalized Zinc Oxide-Mediated Green Photopolymerization of Multinetwork Conductive Eutectogels for Wearable Strain Sensing

Abstract Current strategies for preparing conductive hydrogels (CHs) often inevitably encompass the addition of small-molecule photoinitiators, toxic cross-linkers, or complex polymerization conditions, limiting their broader application in flexible wearable electronics. To address these issues, we developed a green in situ photoinitiation and organic–inorganic hybrid cross-linking strategy based on vinyltrimethoxysilane-modified zinc oxide (VTMS-ZnO). By constructing a deep eutectic solvent (DES) system composed of betaine (BET), itaconic acid (IA), and glycerol (Gly), integrated through poly(ethylene glycol) diacrylate (PEGDA) covalent cross-linking, hydroxyethyl cellulose (HEC) chain entanglement, Zn2+ dynamic coordination, and DES-induced multiple hydrogen-bonding interactions, we successfully fabricated HEC@P(2-hydroxyethyl methacrylate-co-sodium 4-styrenesulfonate) [P(HEMA-co-NaSS)]/VTMS-ZnO semi-IPN conductive eutectogels. In this system, VTMS-ZnO serves as the photoactive inorganic component to induce the in situ copolymerization of HEMA and NaSS under UV irradiation. Moreover, the surface vinyl groups of VTMS-ZnO participate in the network construction, allowing the ZnO nanoparticles to be embedded into the polymer network as hybrid nodes. The optimized H0.2 eutectogel demonstrated an elongation at break of approximately 1000%, a toughness of 96.96 kJ m–3, an ionic conductivity of 78.2 mS m–1, a gauge factor of 0.270, and an adhesion strength of 6.11 kPa on paper. It maintained stable sensing performance over 150 cycles at 10% strain, remained flexible after storage at −53 °C for 12 h, and retained over 50% of its initial mass at 37 °C and 35% relative humidity for 11 days. This comprehensive performance enables the eutectogels to serve as versatile wearable sensors for the real-time monitoring of human movements and weak physiological signals (response time of 0.82 s). In addition, the eutectogel exhibited inhibitory activity against Escherichia coli. Our work sheds light on a feasible and eco-friendly strategy for customizing multifunctional eutectogels, paving the way for innovative flexible wearable devices.