RMIT University engineers have developed a new material with compressive strength and stiffness to improve architectural and product designs.
It is inspired by the skeletal structure of a deep-sea sponge named ‘Venus’s flower basket’, and the double lattice design displays auxetic behaviour.
“Auxetics can absorb and distribute impact energy effectively, making them extremely useful,” said lead author of the latest RMIT study into the structure, Dr Jiaming Ma.
“While most materials get thinner when stretched or fatter when squashed, like rubber, auxetics do the opposite,” Ma said.
However, unlike other natural auxetic materials, the double lattice model overcomes their low stiffness and limited energy absorption capacity limitations.
“Each lattice on its own has traditional deformation behaviour, but if you combine them as nature does in the deep-sea sponge, then it regulates itself and holds its form and outperforms similar materials by quite a significant margin,” Ma said.
Lattice displays stiffness, strength, and can contract when compressed.
Results have found:
- Lattice is 13 times stiffer than existing auxetic materials.
- It can absorb 10 per cent more energy while maintaining its auxetic behaviour
- It has a 60 per cent greater strain range compared to existing designs.
Dr Ngoc San Ha said that the unique combination of these properties has opened several exciting applications for their new material.
“This bioinspired auxetic lattice provides the most solid foundation yet for us to develop next generation sustainable building,” Ha said.
“While this design could have promising applications in sports equipment, PPE and medical applications, our main focus is on the building and construction aspect,” Ma said.