Bioinspired Twisted Brick-Mortar Composites for Adaptive Thermo-Mechanical Impact Protection.

Abstract

Protective materials for harsh environments should dissipate transient impact energy while maintaining mechanical reliability under thermal fluctuations. Here, we report a bioinspired twisted brick-mortar composite that integrates a carbon-nanotube-reinforced photopolymer framework with a mechanically active shear-stiffening gel mortar. The continuously twisted brick architecture redistributes stress waves and guides crack deflection, whereas reversible interfacial hydrogen bonding and dynamic boron-oxygen crosslinking enable rate-dependent molecular dissipation. This structural-molecular coupling provides efficient impact protection, delivering a low energy transfer rate of 7.38% under high-strain-rate compression and reducing the residual impact force from 20°C to 100°C. The carbon-nanotube-containing framework further provides photothermal responsiveness, allowing reversible stifhefness modulation, adaptive force buffering, and shape recovery after localized high-speed impacts. Together, these results establish a bioinspired twisted brick-mortar design strategy for adaptive thermo-mechanical impact protection.