Highly sensitive, anti-freeze, repairable, and conductive double-network organohydrogel for flexible pressure sensors

Abstract

Flexible strain sensors based on double network conductive hydrogels have attracted much attention due to their great potential for human motion health and smart detection. However, the development of conductive hydrogels with high sensitivity and anti-freezing properties for a wide range of use environments is still a challenge. Herein, a novel organohydrogel-based PVA-P-TA-MWCNTs (PPTME) double network capable of pressure and strain sensing was reported with high ambient stability, excellent anti-freezing capability, smart reparability and superior sensitivity. The multiple interactions within the PPTME organohydrogel have been substantiated through Density Functional Theory (DFT) analysis. The organohydrogel utilizing strong hydrogel bonds, crystalline microphases, and chain entanglement of PTA/PVA exhibited good mechanical properties (374%) and excellent cycling performance. Meanwhile, owing to the addition of H2O/EG (ethylene glycol) binary solvent, this organohydrogel exhibited long-term water retention (15 days), anti-freezing properties (−61.9 °C), greatly improving the applications at low temperatures. Furthermore, the assembled pressure sensors showed ultrahigh sensitivity (1.88 kPa−1) in wide detection range (0–266.2 kPa). Based on these excellent properties, a flexible organohydrogel sensor was prepared, demonstrating its enormous potential in the field of human motor behavior detection and wearable.