Nano-enhanced photocurable PAM/TiO₂/β-CD ionogels with high ionic conductivity, mechanical robustness, and anti-drying stability for flexible sensors

A nano-enhanced photocurable polyacrylamide/titanium dioxide/β-cyclodextrin (PAM/TiO₂/β-CD) composite ionogel was fabricated via a multi-component synergistic strategy. TiO₂ nanoparticles act as physical crosslinking points and Lewis acid active sites for mechanical reinforcement and extra ion transport channels, while β-CD realizes uniform TiO₂ dispersion, promotes ionic liquid dissociation, and relaxes the polymer network. Notably, the conductivity of the PAM/TiO₂/β-CD ionogel is 617.76% higher than that of the pristine PAM ionogel (4.11 × 10⁻³ S·m⁻¹), and the optimized ionogel (5 wt.% TiO₂, 2 wt.% β-CD, 20 wt.% [EMIM][TFSI]) achieves a high ionic conductivity of 2.95 × 10⁻² S·m⁻¹, an ultrahigh elongation at break of 1273%, and excellent environmental stability (a mass change < 2.8% after 2 weeks of open-air exposure). Based on this ionogel, a resistive strain sensor (a linear sensing range of 100%–1000% with a gauge factor of 0.765) and an electric double-layer pressure sensor (10.69 × 10⁻³ kPa⁻¹ sensitivity) with superior sensing performance are constructed. An intelligent glove integrated with these sensors is further developed, realizing accurate finger curvature detection, gesture recognition, and palm pressure mapping for human-machine interaction. This work provides a feasible strategy for high-performance ionogels and their applications in flexible electronics.