Novel multifunctional composite ionogels for smart actuation, underwater sensing, and self-powered Braille communication systems

The multifunctional integration properties of biological tissues provide significant bionic insights for designing intelligent materials, driving the advancement of materials science toward multifunctional coupling. Traditional flexible materials often face challenges in achieving property compatibility and functional synergy, especially under complex environments. To address these challenges, this work developed a novel composite ionogel based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and PEDOT:PSS, which exhibits toughness, frost resistance, underwater stability, and shape memory functionality. The incorporation of conductive filler PEDOT:PSS synergistically optimizes the mechanical properties, near-infrared-responsive functionality and conductivity of composite ionogels. The ionogels exhibit superior thermo/light dual-response shape memory behavior, with shape fixation and recovery rates both exceeding 98 %. Based on the light-responsive shape memory performance, the ionogels can lift objects 22 times its own weight and enable real-time monitoring of the actuation process through the resistance variation induced by shape recovery. The ionogel's underwater environmental stability and enhanced conductivity allow its strain sensors to effectively monitor human joint movements, such as finger and wrist bending, in both terrestrial and aquatic environments. Additionally, a self-powered pressure sensor fabricated with this ionogel serving as both the friction and conductive layers exhibits a high sensitivity of 5.890 V kPa⁻¹, enabling real-time human activity capture and facilitating an innovative braille typing assistance system for the visually impaired. This work offers novel insights into the engineering of material properties and the integration of multifunctionalities, thereby promoting the advancement of multifunctional material systems.