Robust conductive organohydrogel strain sensors with wide range linear sensing, UV filtering, anti-freezing and water-retention properties

Abstract

The potential application prospects of conductive hydrogel-based flexible sensors in many emerging electronic devices have prompted intensive research on flexible hydrogel strain sensors to meet the needs of different application scenarios. Herein, by simply immersing PVA organohydrogel compounded with cellulose nanofibers (CNFs) and α-zirconium phosphate (α-ZrP) nanosheets in tannic acid (TA)/NaCl/water solvent, we prepared an organohydrogel strain sensor with excellent mechanical properties, anti-freezing and water-retention properties, transparency and UV filtration, and excellent strain sensing properties. The addition of CNFs and α-ZrP nanosheets could synergistically improve the mechanical properties of the organohydrogel and contributed to the enhancement of electrical conductivity with little effect on the transparency of the organohydrogel. TA was used as a physical cross-linking agent to further improve the strength of the organohydrogels (tensile strength of 5.37 MPa, toughness of 29.06 MJ/m3, elongation at break of 1057%) and as a UV filtering component to impart nearly 100% UV filtering performance to the organohydrogel. In addition, the organohydrogel exhibited an extremely wide linear (R2 = 0.995) sensing range (650%), high sensitivity (GF = 2.78) and excellent cycling stability as a strain sensor to detect human motion. This integrated high-performance TA-PVA/ZC organohydrogel shows great potential for flexible sensors.