3D printed breakthrough for next-generation vehicle crash protection

A collaborative research team from the University of Glasgow, the Polytechnic University of Marche, the University of L’Aquila and Italy’s National Institute for Nuclear Physics has developed a new class of 3D-printed metamaterials that could redefine how vehicles manage impact energy

Published in Advanced Materials, the work introduces adaptive twisting metamaterials - architected steel structures whose mechanical response can be tuned to different crash scenarios without electronics, hydraulics, or active controls.

At the core of the innovation is a gyroid lattice architecture produced through metal additive manufacturing. Gyroid-based structures have long been of interest for their ultra-low density and high strength-to-weight ratio, but the researchers have exploited a unique characteristic: when compressed, the lattice can convert axial strain into a corkscrew-like rotational deformation. This twist provides a new degree of freedom in crash-energy management, enabling programmable stiffness and energy absorption.

PROGRAMMABLE ENERGY ABSORPTION

Conventional crash-mitigation systems such as aluminium crumple zones and polymer foams are inherently static. They are designed for a specific load case and typically cannot adapt to variations in impact direction, magnitude, or rate. Professor Shanmugam Kumar of the University of Glasgow, who led the research, notes that, “the protective materials used in most vehicles today are static, designed for specific impact scenarios and unable to adapt to varying conditions.”

The team instead demonstrated that rotation constraints applied at the boundaries of the gyroid material allow engineers to mechanically tune its behaviour.

Three configurations were tested under both dynamic impacts and quasi-static loading:

• Fully constrained (no twist): Maximum stiffness, absorbing 15.36 J/g of energy – the highest of all configurations
• Freely twisting: Approximately 10% reduction in stiffness and absorption, resulting in a softer, more compliant response
• Over-twisted (forced rotation): A 33% reduction in absorption, illustrating the tunability range

This spectrum, from rigid shielding to compliant cushioning, could enable a single material system to replace today’s mix of crash structures designed for different load cases.

ADVANCED MODELLING AND MANUFACTURING INTEGRATION

To support the experimental work, the researchers developed a computational model capable of predicting gyroid-twist behaviour across strain rates. Importantly, they incorporated real-world manufacturing imperfections into the model by reconstructing the printed lattices using micro-CT scanning. This alignment between numerical and experimental results is critical for validating metamaterial architectures intended for safety-critical applications.

The material is fabricated entirely from steel using additive manufacturing, allowing the precise control needed to generate gyroid lattices with the required porosity and geometric continuity. AM also enables local modifications such as variable pore size or lattice density, opening additional design degrees of freedom for engineers seeking to tailor response zones within vehicle structures.

IMPLICATIONS FOR AUTOMOTIVE ENGINEERING

The potential applications extend far beyond a simple structural insert. Because the gyroid can convert linear impact loads into rotational motion, the material opens new possibilities for rotational-energy absorbers, hybrid crash-mitigation systems and even mechanical impact-energy harvesters. Professor Kumar notes that the metamaterial “could find applications in both automotive and aerospace safety… and could also support the development of novel forms of energy harvesting, by converting impacts into rotational kinetic energy.”

For vehicle manufacturers, the concept aligns with a growing trend toward multifunctional crash structures that offer improved performance without increased weight or complexity. The tunable nature of the material may also reduce the need for complex active safety actuators that must withstand milliseconds-scale loads.

ADAPTIVE, ELECTRONICS-FREE SAFETY SYSTEMS

While still in early development, adaptive twisting metamaterials present a compelling new direction for passive safety engineering. They demonstrate that adaptability can be achieved through architected materials alone, reducing system complexity while offering engineers a new design parameter: rotational freedom.

As regulatory pressures and real-world crash variability continue to grow, architected materials that can dynamically adjust to impact severity may become a cornerstone of next-generation automotive and aerospace protection systems.