Porous bismuth-based liquid metal as multifunctional material

<h2>Summary</h2> Liquid metals own great potential for making multifunctional advanced materials. Gallium-based alloys may not work well for load-bearing situations because of their high density, susceptibility to oxidation, and leakage at room temperature. By contrast, bismuth-based alloys exhibit self-supporting rigidity and heat-induced softening, making them attractive alternatives. Here, we present a sugar-sacrificial-templating strategy for fabricating lightweight porous bismuth-based liquid alloys. By controlling the sieved particle size of the template, this method enables tailored pore structures while reducing the weight of the original metal by more than half and preserving its electrical conductivity and phase-change thermal response. It also provides electromagnetic shielding and internal space for mass transport. Finite element simulations reveal how the pore network regulates stress concentration and electromagnetic wave scattering. The material remains stable under flexible encapsulation and variable temperatures. This work provides a design strategy for bismuth-based multifunctional materials with load-bearing capacity, mass delivery, and tunable electromagnetic protection.