Nature-inspired ceramic fiber aerogels advance thermal insulation

Recently, a research group led by Prof. Wang Zhenyang and Zhang Shudong from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, developed a new type of ceramic fiber aerogel, SiC@SiO₂, featuring highly anisotropic thermal conductivity and extreme thermal stability through directional bio-inspired design.

The work was published in Advanced Science.

In nature, many biological structures—such as wood’s vascular systems or the layered architecture of silkworm cocoons—demonstrate directional heat management thanks to their well-organized internal structures.

Inspired by these natural designs, the team applied a bio-inspired fabrication strategy to create aerogels with similarly ordered architecture. They used electrospinning and freeze-drying techniques to fabricate a highly ordered structure.

First, thermally stable SiC nanofibers with excellent chemical stability were synthesized as basic units, followed by the construction of an amorphous SiO₂ shell on their surfaces. This SiO₂ coating acts as a phonon barrier, enabling both intra-layered alignment and inter-layered stacking to form a highly oriented SiC@SiO₂ ceramic fiber aerogel.

The anisotropic aerogel demonstrates remarkable properties: Ultralow cross-plane thermal conductivity is as low as 0.018 W/m·K, and an anisotropy coefficient is as high as 5.08, which is significantly better than that of similar materials.

In addition to thermal performance, the aerogel shows excellent mechanical resilience, with radial elastic deformation over 60% and axial specific modulus reaching 5.72 kN·m/kg.

Most impressively, it maintains structural and functional stability across an ultra-wide temperature range from -196°C to 1300°C, making it a promising candidate for applications in aerospace, energy systems, and other extreme environments where advanced thermal insulation is critical.

This work offers a new pathway for developing ultralight, high-performance insulation materials for demanding applications, according to the team.