MXene–reinforced dynamic ionogels with synergistic interfacial interactions for high-performance flexible sensing applications

Achieving an optimal balance between mechanical durability and electrical conductivity represents a persistent challenge in the development of soft ionic conductors for wearable sensing technologies. In this study, a dynamic ionogel composed of a 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES)-infused acrylic acid-acrylamide (AA-AAm) copolymer matrix reinforced with Ti₃C₂T_X MXene nanosheets was synthesized via a photopolymerization process. The MXene nanosheets serve as multifunctional dynamic crosslinkers, establishing multiple reversible interactions with the copolymer matrix, including hydrogen bonding, electrostatic interactions, and titanium-oxygen (Ti-O) coordination. These synergistic interfacial couplings contribute to the formation of a hierarchical network that facilitates mechanical energy dissipation while preserving effective ion transport pathways. The optimized ionogel demonstrates exceptional mechanical and electrical performance, including a tensile strain of 699%, tensile strength of 3.04 MPa, toughness of 7.84 MJ·m^-3, ionic conductivity of 0.031 S·m^-1, and self-healing efficiency of approximately 85.4% following 24 hours of recovery. When configured as a flexible strain sensor, the ionogel achieves a rapid response time of 187 milliseconds, a strain detection range up to 300% and maintains stable performance over 2500 mechanical loading-unloading cycles. The sensor enables continuous, real-time monitoring of biomechanical signals, including joint movement, phonation, and arterial pulse waveforms. This study presents a versatile interfacial engineering strategy for the fabrication of MXene-based dynamic ionogels, offering a promising platform for the development of mechanically resilient and electrically stable materials intended for next-generation flexible bioelectronic interfaces.