Mimosa-mimetic hollow yttria-stabilized ZrO2 fibers shaped by temperature and humidity induction for thermal superinsulation

Ceramic fiber materials are highly efficient, chemically stable, and high-temperature-resistant materials but the solid structure of traditional ceramic fibers limits their potential for lightweight design and for improving thermal insulation performance. Here, inspired by the stimulus-response mechanism of the mimosa, we propose a biomimetic strategy based on temperature and humidity field induction to develop yttria-stabilized zirconia (YSZ) fibers with a hollow structure, thereby fabricating lamellar ceramic fiber felts that exhibit both favorable mechanical properties and excellent thermal insulation performance. Benefiting from the enhanced thermal insulation of the hollow structure, the thermal conductivity of these ceramic fiber felts (0.022 W/(m·K) at 25 °C and 0.105 W/(m·K) at 1000 °C) is superior to that of most insulation materials. In addition, the developed ceramic felts feature low density (52 mg/cm 3 ), good tensile strength (360.01 ± 11.38 kPa), and excellent thermal stability, with the tensile strength retaining 90% of the original value even after calcination at 1100 °C. As a pivotal proof-of-concept, the successful preparation of such biomimetic materials establishes a novel research paradigm for the development of hollow ceramic fiber materials.