Bioinspired rubber-like superelastic fibrous ceramic aerogels with record-high strength-flexibility

Fibrous ceramic aerogels are crucial for thermal protection systems; however, their application is often constrained by an inherent trade-off between mechanical strength and flexibility. Herein, we demonstrate fibrous ceramic aerogels with a spiderweb–interspring structure, achieving a record-high strength (0.17 ∼ 4.22 MPa) that is two orders of magnitude greater than that of previously reported ceramic aerogels. Crucially, the aerogels demonstrate an unprecedented combination of exceptional flexibility, superelasticity, satisfactory stiffness, and a near zero Poisson’s ratio, contributing to remarkable dimensional stability. The rubber-like mechanical robustness remains consistent across an extreme temperature range (−196 ℃ to 1200 ℃). The aerogels also exhibit excellent thermal insulation (0.029W m⁻¹K⁻¹) through a high porosity of 96.36% at a density of 80 mg/cm³, effectively resolving the insulation-strength conflict. Our findings indicate that the exceptional mechanical properties are attributed to a spiderweb fiber layer and interspersed x-shaped deformable units, which are constructed from chopped silica fibers with gradient length. The superior thermomechanical performance guarantees reliable operation under extreme conditions, including thermal shock, high-frequency vibration, and large bending strains, thereby advancing the application of fibrous ceramic aerogels in future technologies.