Tough and anti-fatigue double network gelatin/polyacrylamide/DMSO/Na2SO4 ionic conductive organohydrogel for flexible strain sensor

• A facile strategy is proposed to prepare high performance organohydrogel with multifunctional properties, • Gelatin/PAM/DMSO/Na 2 SO 4 (GPDN) organohydrogels displayed splendid mechanical properties. • GPDN showed the high anti-fatigue property over 1000 tensile cycles at a fixed strain of 300% without obvious plastic deformation. • GPDN based sensor could detect multiple external stimuli with high sensitivity (gauge factor of 7.13) and favorable cyclic stability. High mechanical stability during cyclic tensile loading–unloading courses is critical for the actual applications of hydrogels in the wearable electronic equipment and human–machine interfaces. However, the conventional hydrogels prominently confront poor mechanical performances and are subjected to fatigue fracture under continuous loading–unloading cycles. Herein, a facile strategy is proposed to prepare a hybrid physically and chemically crosslinked double network organohydrogel. The gelatin forms the physically cross-linked network through sol–gel transition and salting-out effect. The poly(acrylamide) (PAM) chains construct the chemically cross-linked network. The prepared gelatin/PAM/DMSO/Na 2 SO 4 (GPDN) organohydrogels displayed splendid mechanical properties. Furthermore, GPDN organohydrogels showed the high anti-fatigue property over 1000 tensile cycles at the fixed strain of 300% without obvious plastic deformation. In particular, the GPDN organohydrogel displayed high ionic conductivity and could be used as the strain sensor to detect multiple external stimuli (tension, compression, and bending) with high sensitivity (gauge factor of 7.13) and favorable cyclic stability.