Dielectric-Conductive Dual-Shell Structure Design Overcome the Lightweight-High Strength and Electrical-Thermal...

The advancement of modern electronic devices toward lightweighting, high-frequency, and integrated designs has escalated the demand for multifunctional materials that can combine microwave and thermal management capabilities with mechanical load-bearing capacity. However, inherent trade-offs exist between electrical conductivity and thermal insulation, as well as between mechanical strength and lightweight properties. Herein, attempts have been made to innovatively embed lightweight, high-strength dielectric shells and highly conductive, low-infrared-emissivity metallic shells into hollow structure design. Specifically, heterogeneous dual-shell hollow microspheres (DSHM) were constructed using glass as the model dielectric material and copper as the conductive material. By optimizing the ratio of dielectric-to-conductive phases, the shell microstructure, and macroscopic structural parameters, we achieved a synergistic combination of lightweight and high strength (density: 0.4456-1.0991 g cm^{- 3}, survival rate under 2 MPa uniaxial compression: 87.1%. Crucially, leveraging the distinct structural dependence of conductive and thermal networks, the integration of low thermal conductivity (0.1134-0.1478 W m^{- 1} K^{- 1}) with broadly tunable electrical conductivity (299.6-2625.7 S cm^{- 1}) and infrared emissivity (0.218-0.493) in a single microsphere was achieved for the first time. These properties endow the hollow microspheres with exceptional microwave attenuation and thermal regulation performance.