Nature Commun. 3, 1164 (2012)

Credit: © 2012 NPG

The mechanical properties of materials subject to extremely high deformation rates and large strain are crucial for their use in technologies such as jet engine turbine blades and body armour. Although these phenomena have been extensively studied in conventional materials such as metals, ceramics and polymers, they are less well understood in nanoscale composites. Edwin Thomas and colleagues examine the response of a composite material consisting of alternating glassy and rubbery layers to microscopic bullets, and find a significant enhancement in their capacity to stop the projectiles. Using scanning electron microscopy techniques with a resolution below 10 nm, they observe how the layered structure of the composite dissipates the energy of the impact through a range of processes including kinking, layer compression and domain fragmentation, to form a liquid phase. This unique behaviour opens up an entire family of layered composites, which may lead to increasingly light and thin protective coatings for a range of different technologies.