A stretchable, self-adhesive, conductive double-network hydrogel and its application in flexible strain sensors

Conductive hydrogels possess both the physicochemical properties of hydrogels and the electrical properties of intrinsically conductive polymers. It is a versatile material that is widely used in various fields, such as supercapacitors, flexible energy storage, electronic devices, and sensors. Conductive hydrogels with self-adhesion properties can realize self-adhesion on the surface of the detected object to ensure the stability of detection signals. Inspired by the adhesion mechanism of mussels, tannic acid (TA) was modified on carbon nanotubes (TA-CNTs) were prepared on the surface of (MWCNT), which reduced the aggregation of carbon nanotubes, increased the dispersibility of carbon nanotubes in the hydrogel, and achieved good electrical conductivity and self-adhesion of the hydrogel, sodium alginate (SA), TA-CNTs synthesized a stretchable, self-adhesive, conductive double-network hydrogel by one-pot thermal initiation with stability. Hydrogen bonds between PAM and SA, which helps to construct the hydrogel networks with strong mechanical properties. The synthesized hydrogels have high strength, pliable adhesion, and strain sensitivity, showing great development potential in monitoring human motion and personal healthcare applications.