3D or not 3D (printing)

“At the moment in New Zealand, the state of additive manufacturing is probably at a medium level. We’re not leading the world, but we’re not trailing the world either,” says Olaf Diegel, a professor of additive manufacturing in the Faculty of Engineering and Design, Mechanical and Mechatronics Engineering at the University of Auckland. “We’re starting to see it used for real-world engineering applications, but not as much as in some countries like the United States and in Europe in particular.”

Such medium-level progress can be attributed to equating 3D printing only with prototyping. Olaf calls it a “misunderstanding” that most companies still think they can’t implement 3D printing for production. “But in general, you can,” he says.

The key, Olaf notes, is to use 3D printing to add value, forging a product that is better than if it was made with conventional manufacturing. “If you’re not adding that substantial amount of value, it becomes an expensive manufacturing proposition.”

3D printing also uncovers a realm of possibilities when it comes to engineering innovations in Aotearoa. “I think the potential is huge… We need New Zealand companies to start doing new things rather than business as usual because we’re trying to compete with the rest of the world. We need some more innovative applications of additives,” Olaf says.

Transformative possibilities

In the world of healthcare, engineers harness 3D printing to help enhance patient outcomes. Dr Maedeh Amirpour, a senior lecturer in engineering science and biomedical engineering at the University of Auckland, is developing wearable human interfaces and prosthetics with the help of 3D printing. Her recent work revolves around custom orthotic insoles to reduce pain and pressure under the feet.

Maedeh and her team begin by taking a scan of the foot or part of the limb to get an exact digital map of its anatomy and geometry. Next, they run a computational simulation and optimisation algorithm to design and predict how the orthotic device will behave during day-to-day movements such as walking or climbing steps. Then, they run tests to ensure the optimised 3D-printed personalised device can cope with real-world use.

Accuracy, comfort, quality and safety are integrated into every step of the process.

“By combining the scans, advanced computational modelling and 3D printing, we can create orthotic insoles that are not only comfortable but also built to last in real-life conditions,” Maedeh says. “If our computational model shows that the design might be too stiff or too weak, we can optimise it based on our algorithm before it’s ever printed.”

The orthotic insoles are made from a blend of biocompatible resin and hydrogel. Resin forms a durable outer shell for support, while soft hydrogel supplies comfort. Through 3D printing, each orthotic device is tailored to a patient’s needs, enabling them to rapidly adapt to it and providing them with a cost-effective option.

“Traditional prosthetics and orthoses often require multiple fittings, long wait times and expensive tooling. With 3D printing, once we have the scan and digital model, we can produce a device quickly without wasting materials and at the fraction of the cost of other methods,” says Maedeh. “It also gives us the freedom to create shapes and a lightweight structure that’s strong but flexible – similar to how nature designed our bones.”

Most of Maedeh’s current work is happening at the lab, where prototypes are tested and refined. To deliver their solution at a larger scale, the team needs to obtain funding and investment for clinical trials.

“The beauty of 3D printing is that scaling becomes much easier because the process is digital,” Maedeh says. “It ensures people get solutions that fit their bodies perfectly. Whether it is a child needing a fast-growing prosthetic or an older adult needing a pain-free insole, 3D printing can definitely help.”

Meanwhile, Dr Rachael Wood, a senior lecturer in chemical and process engineering at the University of Canterbury, has embarked on a research project to fabricate 3D-printed bioscaffolds that support neural regrowth after a spinal cord injury. These bioscaffolds will be implanted into the body, guiding the growth of new cells. As a framework for cell regeneration, they will help reconnect damaged neurons in the spinal cord and restore function.

Rachael and her team will apply a method known as cell imprinting.

“The idea is to get the physical imprint of the cells,” she says. They can grow the cells, form moulds of them, and build 3D models of the moulds to make ‘fake’ cells.

“If we use 3D printing, we can do that accurately and then we can make changes easily.”

The team must also choose the right bioink to print with, allowing the cells to hold the structure and grow on it.

“It has to be something we can put in a body, can be imaged, and can be handled and actually implanted by surgeons,” explains Rachael. “And if we put any cells’ chemical signals in a bioink, we need to make sure the cells can still extract them.”

While the project is in its beginning phases, Rachael hopes to offer transformative possibilities for those with a spinal cord injury, and 3D printing can boost those possibilities.

“It opens the door for more personalised medicine and solutions that will be more comfortable for the patient and bring about better patient outcomes,” she says.

“Because it’s not always going to be one-size-fits-all. Making something that’s uniquely built for the patient can have a real impact.”

Modelling a 3D-printed future

Looking ahead, Olaf sees generative AI assisting with designing the right way for 3D printing.

“The one truth you can’t get away with in additive manufacturing is you need a 3D model.” This can be a challenge for organisations without the necessary design skills, which is where generative AI comes in.

“We’re using AI to create the computational design, and it can generate the model instantly. You still tell it what you want, and in a few minutes, you’ve got your parts ready to print,” he says.

And in the factory of tomorrow, Olaf envisions a trifecta of CNC machines, injection moulders, and 3D printers all sitting side by side, working together to yield the next generation of engineering innovations.

Can they 3D print it?

Sutton Tools began using 3D printing for prototypes to test machine components. “When we started using it, we realised all the possibilities,” says Richard Frew, engineering manager at the firm’s manufacturing plant in Rangiora, Canterbury.

They’ve moved beyond prototyping to printing multiple tooling and parts – from complex machine guarding and custom extraction adaptors to non-structural mounting brackets for machines. 

“3D printing is a good way to make new iterations, refine things and make sure everything’s going to fit in,” he says.

Packaging automation has been a key growth area. “Instead of spending large amounts of money on a wide range of tooling to handle the many drill sizes we manufacture, 3D-printed tooling can be made ‘lights out’ overnight at a low cost,” says Richard.

“We have also found that this tooling lasts well in our production environment and can be customised with extra features that would be difficult and expensive to machine conventionally.”

While Sutton Tools mostly prints with plastic materials, they also work with carbon fibre and hope to move to metal 3D printing as it becomes more affordable. After all, their motto has been and continues to be: “We could 3D print that!”

Concrete changes

3D-printed concrete can lead to swifter build times, lower cost and less waste than conventional construction methods. Poornima Rao Telikicherla, a PhD student at the University of Canterbury’s Department of Civil and Natural Resources Engineering, says it’s still an emerging technology compared to a regular reinforced concrete or masonry building.

Poornima’s research entails improving the seismic performance of 3D-printed concrete structures. She aims to define the behaviour and performance of 3D-printed walls during an earthquake by conducting quasi-static tests on reinforced 3D-printed rectangular walls.

Despite being in the early stages of testing, she says 3D-printed concrete has a lot of potential. Her final goal is to formulate guidelines that could help architects and engineers design and build these structures.

“If you have a certain force that a structure would be experiencing, how would you even design these walls? That’s the ultimate question I want to answer.”

3D printed instruments strike chord

During his spare time, Olaf Diegel 3D prints guitars, a hobby he started more than a decade ago. “I used to play a lot of music in my younger days, so I printed my first one just to see if it could be done. I was amazed by how well it played and how good it sounded.”

After posting a blog about it, he received emails from musicians around the world who’d never seen anything quite like his eclectic string instruments, which he named ODD Guitars. He has since designed more than a dozen electric guitars, and built and sold more than 100. The University of Auckland and Eden Park even gifted one of his 3D-printed guitars to Coldplay during one of the band’s Auckland concerts in 2024.

Olaf has now expanded to 3D printing bass guitars, drum kits and keyboards.

This article was first published in the December 2025 issue of EG magazine.