A pioneering 3D-printed metamaterial promises to transform vehicle safety measures. Developed by researchers from Scottish and Italian universities, this material features a distinctive lattice design that allows it to twist when subjected to impact, effectively mitigating damage. The material’s adaptive nature means it can mechanically adjust to absorb varying levels of energy, setting it apart from traditional impact protection solutions.
The study, published in Advanced Materials, highlights the material’s innovative approach compared to conventional foams and crumple zones, which offer fixed resistance. This metamaterial can be mechanically controlled to provide either stiffer resistance for severe impacts or softer cushioning for lighter ones. Crafted from steel using additive manufacturing, the material’s architecture is meticulously designed, incorporating a gyroid lattice that enables its unique properties.
Laboratory tests demonstrated the material’s ability to twist in a corkscrew-like motion upon compression, efficiently absorbing impact energy. Researchers evaluated three configurations under different loading conditions: rapid impacts and steady strains. When restricted from twisting, the material achieved maximum stiffness, absorbing 15.36 joules per gram. Conversely, allowing free twisting reduced energy absorption by about 10%, while over-twisting decreased it by 33%. These findings indicate the material’s potential to provide a spectrum of protection, from rigid barriers to softer energy absorption.
Supported by a robust theoretical and computational model, the research accurately predicts the behaviour of twisting gyroid lattices under varied strain rates. Micro-CT reconstructions of the printed lattices were utilised to account for geometric imperfections from the additive manufacturing process.
Professor Shanmugam Kumar of the University of Glasgow led the research, emphasising the static nature of current vehicle protective materials and the potential of adaptive twisting metamaterials. These materials, devoid of complex electronics or hydraulics, adapt through mechanical rotation control, altering energy absorption characteristics to suit impact types and severities. Applications in automotive and aerospace safety are envisaged, alongside potential energy harvesting innovations by converting impacts into rotational kinetic energy.
Collaborators from the Polytechnic University of Marche, the University of L’Aquila, and the National Institute for Nuclear Physics in Italy contributed to this groundbreaking work, co-authoring the published paper, “Adaptive Twisting Metamaterials,” in Advanced Materials.
