Ultrahigh Damping Capacities in Lightweight Structural Materials

The demand to outperform current technologies pushes scientists to develop novel strategies, which enable the fabrication of materials with exceptional properties. Along this line, lightweight structural materials are of great interest due to their versatile applicability as sensors, catalysts, battery electrodes, and acoustic or mechanical dampers. Here, we report a strategy to design ultralight (ρ = 3 mg/cm³) and hierarchically structured ceramic scaffolds of macroscopic size. Such scaffolds exhibit mechanical reversibility comparable to that of microscopic metamaterials, leading to a macroscopically remarkable dynamic mechanical performance. Upon mechanical loading, these scaffolds show a deformation mechanism similar to polyurethane foams, and this resilience yields ultrahigh damping capacities, tan δ, of up to 0.47.