Environmentally tolerant conductive organohydrogel toward superior electromagnetic interference shielding and human motion detection

Abstract

Flexible wearable devices require conductive hydrogels that can withstand extreme conditions. Yet, most strategies for improving environmental tolerance compromise other properties, including mechanical modulus and electromagnetic interference (EMI) shielding. Herein, we design polyvinyl alcohol/polypyrrole double-network organohydrogels with tunable EMI shielding and mechanical properties by introducing specific ions and glycerol. The synergistic effect of high-concentration “salting-in” ions and glycerol/water systems enables 3 M AlCl₃-treated organohydrogels to exhibit exceptional environmental tolerance. These gels display excellent shielding performance above 40 dB and enhanced modulus-like human skin. Glycerol restores the mechanical properties deteriorated by “salting-in” ions, and AlCl₃ promotes ion migration to improve EMI shielding. Additionally, these organohydrogels can also serve as strain sensors, monitoring human motions and maintaining stable shielding (>25 dB) even after subzero treatment or long-term use. Overall, this work offers a generalizable strategy for fabricating multifunctional organohydrogels, paving the way for advancements in gel-based flexible wearable devices.