An environmentally tolerant, highly stable, cellulose nanofiber-reinforced, conductive hydrogel multifunctional sensor

The application of flexible multifunctional sensors based on conductive hydrogels in human health detection has been widely studied. Herein, a facile one-pot method is proposed to prepare ionic conductive hydrogels by dissolving polyvinyl alcohol (PVA), cellulose nanofiber (CNF), and aluminum chloride hexahydrate (AlCl3·6H2O) in a dimethyl sulfoxide (DMSO)/water binary solvent. The resulting ionically-conductive organohydrogels have high stretchability (up to 696%), fast response (130 ms), wide operating temperature (-50 °C to 50 °C), and long-term stability (30 days). The hydrogel sensor exhibits excellent signal sensing capability (human motion and sound detection signals) and cycling stability (1000 cycles) under extreme temperature and long-term storage conditions. Notably, the organohydrogel displays high sensitivity to both compressive deformation and temperature, resulting in multifunctional sensing performance. This work provides a viable approach for the long-term use of hydrogels as wearable devices in extreme environments and daily life.