Effective heat dissipation remains a grand challenge for energy-dense devices and systems. As heterogeneous integration becomes increasingly inevitable in electronics, thermal resistance at interfaces has emerged as a critical bottleneck for thermal management. However, existing thermal interface solutions are constrained by either high thermal resistance or poor reliability. We report a strategy to create printable, high-performance liquid-infused nanostructured composites, comprising a mechanically soft and thermally conductive double-sided Cu nanowire array scaffold infused with a customized thermal-bridge liquid that suppresses contact thermal resistance. The liquid infusion concept is versatile for a broad range of thermal interface applications. Remarkably, the liquid metal infused nanostructured composite exhibits an ultra-low thermal resistance <1 mm² K W^-1 at interface, outperforming state-of-the-art thermal interface materials on chip-cooling. The high reliability of the nanostructured composites enables undegraded performance through extreme temperature cycling. We envision liquid-infused nanostructured composites as a universal thermal interface solution for cooling applications in data centers, GPU/CPU systems, solid-state lasers, and LEDs.

Understanding radiation responses of Fe-based metals is essential to develop radiation tolerant steels for longer and safer life cycles in harsh reactor environments. Nanograined metals have been explored as self-healing materials due to point-defect recombination at grain boundaries. The fundamental defect-boundary interactions, however, are not yet well understood. We discover that the interactions are always mediated by formation and annealing of chain-like defects, which consist of alternately positioned interstitials and vacancies. These chain-like defects are closely correlated to the patterns of defect formation energy minima on the grain boundary, which depend on specific boundary configurations. Through chain-like defects, a point defect effectively translates large distances, to annihilate with its opposite, thus grain boundaries act as highly efficient defect sinks that cannot saturate under extreme radiation conditions.