Revolutionizing impact absorption: breakthrough metamaterials for safer and reusable shock absorbers

Traditional mechanical metamaterials often rely on reversible elastic deformations, similar to a rubber band, allowing them to return to their original shape after bending or stretching. However, this approach limits their stiffness and strength. The team, led by physicist Corentin Coulais, has demonstrated that integrating plastic deformations into the design of metamaterials can result in ideal shock absorbers. This innovation combines stiffness and load-bearing capacity with flexibility, which is essential for efficiently absorbing sudden shocks.

The researchers manufactured the new metamaterials using a metal 3D printer and traditional production methods. They subjected the designs to extensive crash tests using a refurbished hydraulic fracture machine, a powerful test device nicknamed “Smashzilla,” and a three-story industrial drop tower at Tata Steel Netherlands.

The design of these metamaterials balances the plasticity of the base material with the flexibility of the geometric structures, resulting in sequential buckling under pressure. This controlled buckling allows for efficient dissipation of impact energy while maintaining load-bearing capacity. Moreover, these shock absorbers can be reused multiple times and even repaired for a second lifecycle, unlike traditional shock absorbers, which lose their stiffness and strength after deformation.

This new class of sequentially buckling metamaterials can be made from any elastoplastic material and is suitable for mass production. The structural design can be tailored for diverse applications. According to Bernard Ennis of Tata Steel Netherlands, this technology has the potential to revolutionize shock absorption in the automotive, aerospace, and construction industries and enables the design of customized materials at various scales.

The findings of this research have been published in the journal Nature under the title “Harnessing plasticity in sequential metamaterials for ideal shock absorption.”