Multilayer Bioinspired Heterogeneous Superelastic Ceramic Aerogel for Robust Signal Detection Under Extreme High-Temperature Conditions.

Simultaneously achieving mechanical compliance and thermal resilience in piezoelectric sensors remains a longstanding challenge, as it requires reconciling the intrinsic brittleness of ceramics with the thermal instability of polymers. Here, we engineer a bioinspired, super-elastic ceramic nanofiber aerogel with a hierarchical BaTiO3 embedded in an amorphous Al2O3-SiO2 aluminosilicate network sandwich architecture to resolve this trade-off. Mimicking the thermoregulatory defense mechanism of desert lizard skin, this design leverages a scalable spinning self-assembly strategy to create a mechanically confined heterostructure. The exterior entangled amorphous Al2O3-SiO2 aluminosilicate (AS) fiber networks serve as a dual-functional barrier, effectively decoupling the piezoelectric BaTiO3 core from external thermal shocks while synergistically diffusing localized compressive stress via a multi-layer effect. This architectural engineering enables the aerogel to sustain stable piezoelectric functionality at temperatures exceeding 800°C-far surpassing the conventional 120°C limit of BaTiO3. Furthermore, the aerogel exhibits an ultralow density (4.5 mg·cm-3), superior thermal insulation (0.029 W·m-1·K-1), and exceptional piezoelectric stability (10 000 cycles). This work addresses the trade-off between flexibility and thermal stability in piezoelectric materials, providing a promising design strategy for durable, high-performance sensors that operate in extreme environments.