A dual-bioinspired structural design enables highly efficient microwave absorption and thermal insulation in SiC hybrid aerogels

Abstract

A critical challenge in developing microwave–infrared dual-band stealth technology lies in constructing multifunctional materials that achieve both broadband electromagnetic-wave absorption and efficient thermal insulation. Inspired by polar bear hair (hollow structure) for thermal insulation and Parotia wahnesi crown feathers (array structure) for light trapping, we engineered a bioinspired SiC hybrid aerogel comprising hollow microtubes and in situ grown nanowire arrays, thereby forming multiscale interfaces such as tube–nanowire junctions, nanowire–catalyst contacts, SiC core–SiO₂ shell heterostructures, and 3C/2H SiC phase boundaries. Through the synergistic combination of the macroscopic hierarchical architecture and precise multiscale interface engineering, the SiC hybrid aerogels achieve exceptional multifunctional performance. By carefully regulating the thickness of the SiO₂ shell via the oxidation temperature, optimal impedance matching and enhanced polarization loss are attained. The SiC aerogel oxidized at 1100 °C exhibits superior microwave absorption, with an effective absorption bandwidth of 5.525 GHz (12.475–18 GHz) at a thickness of only 1.65 mm and a minimum reflection loss of −51.75 dB at 1.45 mm. Simultaneously, the bioinspired multiscale porous architecture effectively suppresses heat conduction, endowing the SiC hybrid aerogel with excellent thermal insulation properties. This work demonstrates that integrating bioinspired structural design with multiscale interface engineering offers an effective strategy for developing high-performance, multifunctional materials with dual-band stealth and thermal protection.