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 h of recovery. When configured as a flexible strain sensor, the ionogel achieves a rapid response time of 187 milliseconds and 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.