Super-stretchable and negative-Poisson-ratio meta-aerogels

Highly stretchable aerogels are promising for flexible electronics but their fabrication is a great challenge. Herein, several kinds of unprecedented intrinsically highly stretchable conductive aerogels with low or negative Poisson’s ratios are achieved by uniaxial, biaxial, and triaxial hot-pressing strategies. The highly elastic reduced graphene oxide/polymer nanocomposite aerogels with compressed and folded porous structures obtained by the uniaxial hot-pressing method exhibit record-high stretchability up to 1200% strain, significantly surpassing all those of the reported intrinsically stretchable aerogels (usually ≤200%). In addition, the meta-aerogels with reentrant porous structures that combine high biaxial stretchability and negative Poisson’s ratios have been obtained by the biaxial hot-pressing method for the first time. Furthermore, the never-before-realized meta-aerogels combining high triaxial stretchability and negative Poisson’s ratios have been achieved by constructing the reentrant porous structures via the triaxial hot-pressing method. The wearable strain sensors based on the resulting aerogels exhibit a record-wide response range (0-1200%). In addition, they can be applied for smart thermal management and electromagnetic interference shielding, which are achieved by regulating the porous microstructures simply via stretching. This work provides a versatile and simple strategy to highly stretchable and negative-Poisson-ratio aerogels promising for various applications including but not limited to flexible electronics, thermal management, electromagnetic shielding, and energy storage.