Biomimicry for the Modern World: Lee Djumas
Words by Nikki Stefanoff
Photos by Björn Rust
This content is produced in partnership with Monash Materials Science and Engineering
While technology is the answer to a lot of our problems, there’s still a lot to be said for looking to Mother Nature for answers. After all, she’s been getting it right for millennia.
Monash University’s Department of Materials Science and Engineering looks like a scene from an 80s movie where the protoganist tries to imagine what the 'future' might look like. It's white, it's clinical and, yes, there are 3D printers the size of tents and high-tech digital platforms as far as the eye can see but it’s also a warm and welcoming space. Somewhere innovation and creativity collide, where students’ independent thinking is supported and problem solving is encouraged.
One such student is Lee Djumas who, after studying for a double degree in science and engineering, was invited to stay on with the department and study for his PhD. Djumas had already majored in materials science as part of his engineering degree and had become fascinated with how he could explore the creation of multi-material structures but also remain inspired by nature.
“I became really interested in the concept of topological interlocking, which in layman’s terms is like a 3D jigsaw puzzle where all parts are identical,” Djumas explains. “My aim was to create a material that was both strong and tough by using the department’s Connex500 3D printer. The printer is revolutionary because of its ability to print materials like soft rubbers and stiff plastics down to 30 microns either side-by-side or mixed together, which opened up a whole world of design freedom for me. I could start to explore how I could create hybrid multi-materials that were both stiff and tough, which is the ultimate for materials engineers.”
The way Djumas looked to combine materials was bio-inspired, particularly through the natural form of nacre. “Nacre is part of the mollusc shell and made almost entirely of calcium carbonate [chalk], so it should be very brittle,” he says. “But it also has a bit of bio-polymer in there, which is really just glue. The way in which all this is arranged makes the shell tougher than it should be, making it a beautiful example of nature’s architecture.”
People have been trying to understand nacre for years. In particular, how it breaks and reveals its structural hierarchy. Djumas isn’t the first person to attempt to recreate nacre either – a team at Massachusetts Institute of Technology (MIT) in Boston successfully printed a 2D version, however, Djumas wanted to go one better. He visited the MIT lab and left inspired to take this 2D structure, incorporate the geometry of topological interlocking over the top and print a 3D version. He was successful and along the way discovered that by adding a 3D element to the 2D structure the strength and toughness of the man-made nacre had been increased.
Despite potential for a variety of commercial applications, Djumas didn’t set out to create something for money. For him, it was more about the journey of discovery and to demonstrate his ability to think creatively. “I feel that creativity is the understated skill in engineering. The role of creativity in science and engineering is almost never spoken of,” he says. “Without creative thinking you can’t do any meaningful research or innovate. For me, the idea of applied creativity is what innovation is all about: engineers make things and to make things that haven’t been made before you need to be creative. Inspiration can come from many different places and for us in our department that happens to be nature. It’s elegant. The more you look into how nature has solved problems over the years… it’s a beautiful thing and hard not to get inspired by it.”
“The way in which all this is arranged makes the shell tougher than it should be, making it a beautiful example of nature’s architecture.”