Researchers at NYU Abu Dhabi have uncovered the secret behind the remarkable toughness of the marri nut, the hard seed of the marri tree native to Western Australia. The nut’s shell is so strong that even natural predators struggle to break it. By studying how it absorbs impact and resists cracking, the team discovered a clever natural design that could inspire new materials for protective gear and other safety applications.
The study, published in Advanced Science, shows that the marri nut’s strength comes from a layered internal structure that combines a tough outer shell with a softer, flexible interior. This combination of hardness and flexibility allows the nut to absorb energy without shattering, distributing force in a controlled way rather than breaking suddenly.
The research, conducted over five years by the Smart Materials Lab (SML) at the Center for Smart Engineering Materials (CSEM), used advanced 3D imaging and mechanical testing to examine how the nut behaves under pressure. Despite being largely made of cellulose, a natural plant material, the nut displayed a rare combination of properties: it can deform and absorb energy like Teflon, while maintaining stiffness similar to acrylic, all while remaining lightweight.
Inspired by the nut’s design, the researchers created a bioinspired material that mimics its internal structure. The work demonstrates how natural designs that evolved over millions of years can guide the development of materials that are both lightweight and impact-resistant.
This research was supported by the NYU Abu Dhabi Research Institute.
