Highly Stretchable MXene‐based Meta‐Aerogels with Near‐Zero and Negative Poisson's Ratios

Abstract MXene‐based aerogels are promising candidates for wearable electronics due to their unique structures and properties. However, the reported MXene‐based aerogels show poor stretchability, significantly restricting their applications in wearable electronics. Herein, unprecedented highly stretchable MXene‐based aerogels with crimpled and reentrant microstructures are developed via synergistic assembly of MXene and flexible polymers combined with uniaxial and biaxial hot‐pressing strategies. The uniaxially hot‐pressed MXene‐based meta‐aerogels show compressed and crimpled microstructures and combine ultrahigh stretchability up to 427%, high elasticity, high compressibility, high fatigue resistance upon compression and stretching, and near‐zero Poisson's ratios. The biaxially hot‐pressed MXene‐based meta‐aerogels exhibit reentrant microstructures and achieve high stretchability and negative Poisson's ratios upon stretching in different directions, which have never been realized by traditional aerogels. It is demonstrated that they can be used for ultrabroad‐range pressure/strain sensors, highly stretchable triboelectric nanogenerators, and smart thermal management with tunable thermal insulation and Joule heating performances achieved by stretching. This work opens a new way to highly stretchable aerogels with near‐zero and negative Poisson's ratios promising in wearable electronics, nanogenerators, thermal management, energy storage, etc.