Weaving sustainability into science

Through science, engineering and innovation, the University of Waikato is helping protect the planet for future generations

University of Waikato researchers are hard at work in the lab, using the building blocks of nature to create renewable materials and keep the worst of our waste out of landfills. Our researchers are working with the latest technology to cut back on pollutants, finding stronger, more eco-friendly ways to build our homes, workplaces and everyday products. They are looking at how to weave sustainability into society, ensuring a viable future for us all.

Engineering new materials

Millions of tonnes of solid waste are generated every day, a problem that is gradually weighing the world down. Professor Kim Pickering is helping to reduce this dangerous tide of waste, through research that is also inspiring new generations of researchers in New Zealand and internationally.

Professor Pickering’s research is focused on composite materials, which combine fibres from things as diverse as hemp and harakeke, to waste plastics. The end products can range from biodegradable plant pots to skateboards.

These composite materials can also be used in 3D printing, with natural fibres and recycled or bio-derived/bio-degradable plastic forming the filament ‘ink’ for 3D printers.

Professor Pickering uses a cocktail of materials such as hemp and recycled building materials to make the filament coil, which is fed into the printer, heated, then pumped out in layers to create a 3D object.

This could be a shoe, a cellphone cover or a cast for a broken limb; almost anything you can imagine can be printed in 3D.

Internationally, 3D printing is a huge growth market and, at the moment, most available filaments are made out of petroleum-based thermoplastic materials. Professor Pickering says she has created a better option.

“We’ve shown you can get improved mechanical performance using sustainable materials, and extend the range of things people can do with 3D printers, with less environmental impact. And at the end you can recycle the material too.”

The next phase of research includes ‘alignment’; strengthening materials by getting the network of fibres they are made from to mesh the right way, allowing them to take the right loads for uses such as construction. With the right alignment Professor Pickering says, natural fibres could eventually replace glass fibres. “They could be used to make shower cubicles, boats, even bridges.”

Creating composites from materials that are derived from nature, or recycled from old buildings, gives us a new way to think about the space that humans take up, from new office blocks to landfills. Professor Pickering believes that changing our definitions of what can be reused and what becomes trash can have a big impact on the earth.

“The most important issue facing the planet is global warming, but many people are in denial. Humans aren’t behaving in a way that’s sustainable, and we need to take some action.”

Professor Pickering’s commitment to environmental stewardship and sustainability was recently acknowledged by the Royal Society Te Apārangi, which awarded her the Scott Medal in recognition of more than 20 years of innovation in science, engineering and technology.

The selection committee noted her international standing, calling her a role model for colleagues and students on how to work towards a more sustainable planet. 

A hallmark of quality research is that it inspires others to extend it.

Not content with pushing the boundaries in her own work, Professor Pickering is also supervising PhD student Maria Oliveira’s research on rotational molding, which is used to produce hollow objects such as containers and kayaks.

Maria is focusing on some of the same sources, including hemp, but extending the idea to see what else can be made.

The rotational molding process works like creating an Easter egg shell; material is put into the mold and rotated on different axes. By using natural materials, Maria hopes to increase the strength and stiffness of the resulting object, improving the mechanical properties.

By making the materials stronger, she also aims to use less material, eventually replacing petroleum-based products altogether in favour of more ecologically friendly, and efficient, bio-derived or recycled materials.

Maria says she could envision her more eco-friendly processes and composites being used for mass-produced items such as the linings of cars, or even aircraft interiors.

Repurposing animal waste through science

So while hemp and recycled waste may soon be found in our everyday objects, what becomes of surplus animal products? The University of Waikato’s scientists are also tackling this challenge, working to ensure as little as possible goes to waste.

Associate Professor Johan Verbeek and his team have turned their attention to repurposing waste products from the meat industry, using bloodmeal to make Novatein, a thermoplastic polymer that can be industrially shaped to create a range of products, including pegs and plant pots. A decade of research brought Novatein to the market.

“We’re producing it commercially in a factory in Hamilton and the research, all done at the University of Waikato, is ongoing,” Dr Verbeek says.

Aduro Biopolymers has three full-time staff members and Dr Verbeek spends 20% of his time at the factory. The company was founded in 2013 as a spin-off from the University of Waikato’s commercialisation and technology arm. It aims to reduce the impact of plastics on the environment.

Dr Verbeek, currently one of only two New Zealanders in the running for a global award from the Institution of Chemical Engineers (IChemE), admits the process has required perseverance. Lack of commercial funding in the exploratory stages meant progress was slow, but they have now established good relationships with businesses that support research and production.

“Alongside the University we have commercial partners in New Zealand and Australia as we develop bio-derived polymers and materials for use in various sectors, including horticulture, agriculture, manufacturing and construction.”

Creating the building blocks for bio-medicine

Collagen is popularly associated with cosmetics or plastic surgery, but its full potential may be untapped. Safiya Noorzai is using it to create complex microscopic ‘scaffolds’, which could become the building blocks for biomedicine and human organ regeneration.

The University of Waikato PhD student is extracting collagen from animal byproducts, using bullhide from a rendering plant. With the support of a Wallace Corporation scholarship, she is using material from the company’s plants to make something that could help save lives.

Dr Verbeek’s work with blood meal was the starting point for the research. Safiya and her supervisor wondered about using not just the meal, but animal skin as well. The field of tissue engineering is growing swiftly and, because 30% of human body protein is collagen, it is biodegradable and will not be rejected. 

The first few months of research were spent finding the best bovine material to take collagen from. After trying various samples, bullhide gave the best quality, purity and yield. As it’s of no use for leather, it’s usually thrown away.

The next step in the research is making hydrogels from that collagen, which will act as bio-ink for bio-printers, allowing the 3D printing of ‘scaffolds’, the biological base from which tissue can then be built up. Organic scaffolds are better than synthetic bases as they degenerate rather than needing removal.

Among other critical aspects, Safiya is focusing on perfecting the viscosity of the gel, and fibre orientation. Safiya says the scaffold bases could one day even be used to create heart valves, or for kidney regeneration.

“There are thousands of people on surgery waiting lists, so this research could someday save lives. At the same time, people are willing to spend $200 for a collagen cream that won’t do anything for them. That’s why I feel it’s so important for people to understand science.”

Although the science behind their work - and their base materials - vary widely, Safiya says she and the other researchers at the University of Waikato are united in their determination to find solutions to the world’s growing waste and pollution problem.

“We’re working towards making the world a better place by innovating biodegradable materials, especially biopolymers and composite materials. We’re making a difference for the future.”

- Safiya Noorzai