For Dr Phuong (Jonathan) Tran, senior lecturer in advanced manufacturing at RMIT University, the future of building materials comes from looking at what already exists in nature.
“One of the objectives of our research group is to look into nature materials and learn how they’re structured and designed, and how they’ve evolved over millions of years to achieve structures that are very light, but with high performance,” Tran told create.
“For example, take an abalone shell … It lives in a very harsh environment under the seabed and is subjected to pressure underwater and attack by predators. It evolves over millions of years to have an architecture that helps it to sustain in the harsh environment. And that’s where we should focus our learning.”
While researchers have been studying biological structures for many years, Tran says in engineering this has typically been limited to the materials arena.
“There’s never been a strong push for engineers to look at biological material inspiration,” Tran explained.
“Materials engineers have tried really hard to push the limits of materials … [But] how this material can form a structure is also very important, to be able to bring the use of the materials to the next level.
“For example, the abalone shell comprises soft [polymer] and hard [ceramic] materials in a unique brick-and-mortar composite architecture to provide a superior strength compared to individual ones.” 
Tran says the age of 3D-printing and additive manufacturing has opened up new opportunities for researching structures, which previously hadn’t been possible.
“We now have a 3D-printing centre (RMIT Advanced Manufacturing Precinct) with the most advanced machine printing capabilities, which can provide very high-resolution 3D-printing of materials and structures at the size of human hair. This scale is very important, to be able to replicate the structures of these biological materials.”
From micro-sized to mega-scale
So far, the research team has explored the concept of nature materials within automotive, defence and biomedical applications, where lightweight materials of high strength is key.
Next up, Tran and his team, including PhD students Luong Pham, Vuong Nguyen and Chenxi Peng, will explore the concept of nature materials on a larger scale, in construction.
“We’re trying to bring this [nature materials concept] from the smaller scale of biomedical, automotive and defence applications, and scale it up to be used in building and marine construction,” Tran said.
“[For example], in the future, a wall might not be a solid wall – it could be a partition wall, allowing wind and light to come through, while still being very strong … We also hope to design a new type of brick structure, exploiting the architecture from nature, which is less prone to failure when subjected to impact.”
To assist in this endeavour, RMIT recently acquired a new concrete 3D printer. The only machine of its kind in the southern hemisphere, the 5×5 m robotic printer will be used by the team to research the 3D-printing of houses, buildings and other large structures.
“It’s a mobile printer, which means it could [even] go into a remote area and print,” Tran said.
“It creates an opportunity to access different areas where it’s not easy to print those highly complex structures. It’s one of the strengths of 3D printing.”
Tran said wave suppressing architecture is a particular area of interest for research, an increasing concern worldwide with rising sea levels.
“These seawalls and breakwater structures used in coastal engineering … need to be lightweight, with a porous structure so the water can flow through,” he said.
“You don’t want to block the wave completely, because if the wave energy is strong, the wall will be damaged for sure.”
A unique area of research, Tran hopes to explore more dimensions of nature materials in the future, and apply the concept to building highly complex, strong and lightweight architecture, for many engineering applications.
“We are now at the edge of Industry 4.0, where we want to revolutionise the way we create buildings and create materials,” Tran said.
“I think it’s important for us to do research [in this area] and disseminate our research and ensure people know, and maybe even inspire the next generation of engineering students.”