Stretchable Zwitterionic Conductive Hydrogels with Semi-Interpenetrating Network Based on Polyaniline for Flexible Strain Sensors

Stretchable conductive hydrogels are of great significance in wearable electronic devices and tissue engineering scaffolds. In this paper, the zwitterionic polymer network hydrogels are synthesized by radical co-polymerizing acrylic acid (AA) and methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC) in aniline (ANI) aqueous solution followed by oxidation polymerization of ANI to form semi-interpenetrating network hydrogel. The conductive hydrogels are endowed excellent mechanical properties by synergistic effect of electrostatic interaction and hydrogen bonding between the interpenetrating network of PANI and P(AA-co-DMC). The tensile strength reaches up to 0.173 MPa at 576% and the compression strength reaches up to 0.73 MPa at 80%. Meanwhile, the zwitterions and polyaniline ensure hydrogels to obtain conductivity (0.428 s m(-1)). In addition, the as-prepared conductive hydrogels can also be used as ionic skin to accurately monitor various movements of the human body, showing its potential applications in wearable devices and flexible electronic devices.