Self-recoverable, highly adhesive, anti-freezing/drying, organohydrogel stretchable sensors

Abstract

The multifunctional conductive polymer gels have attracted tremendous attention in fabricating flexible, intelligent sensors. However, the low mechanical properties, poor self-adhesive properties or self-healing, and poor tolerance to harsh environments remain challenging for practical applications. Here, poly(3,4-ethylenedioxythiophene) (PEDOT): polystyrene sulfonate (PSS) was incorporated into a covalently connected network poly (acrylic acid-co-N-methylolacrylamide) (P(AA-co-N-MA)) to improve mechanical properties. Then, the organohydrogel with anti-freezing and anti-drying properties was obtained by immersing the hydrogel in ethylene glycol. Due to the dual role of structural design and ethylene glycol, the tensile strain of the organohydrogel reached 6000% without breaking, and its elongation at the break of the organohydrogel after self-healing can still get 1000%. Moreover, the organohydrogel remains flexible at -30 to 100 °C and has good environmental adaptability. And the sensor based on the organohydrogel has the ability of strain sensing, and the sensitivity gauge factor (GF) can reach 25.53. In addition, the organohydrogel can be stuck with various material surfaces. This work provides insights into developing flexible electronic materials resistant to harsh environments and strain sensing.