Tag Archives: material engineering

aerogel

Turning jeans into joints: artificial cartilage from denim aerogel

This aerogel, which is synthesised from recycled denim, shares the material properties of joint cartilage. Image credit: Deakin University.

The team, which includes Deakin scientist Dr Nolene Byrne and PhD candidate Beini Zeng, have been pioneering advanced textile recycling methods in a joint project with Deakin’s Institute for Frontier Materials (IFM) and the School of Engineering.

One of their developments has been the use of recycled textiles to form aerogels.  Aerogels are a class of low density materials with a range of applications, which include water filtration and separators in advanced battery technologies.

Denim is an excellent candidate for forming aerogels because the cotton it is woven from is composed of a natural polymer, cellulose. “Cellulose is a versatile renewable material, so we can use liquid solvents on waste denim to allow it to be dissolved and regenerated into an aerogel,” explains Dr Byrne. The process is known as sol gel synthesis.

Aerogels have highly porous structures and extremely low densities. Dr Byrne describes the synthesis of the artificial cartilage aerogel as an unexpected discovery. “It has a unique porous structure and nanoscopic tunnels running through the sample. That’s exactly what cartilage looks like,” she said.

This surprising finding is particularly exciting because of the challenges involved with trying to control the properties of artificial cartilage in tissue engineering. “You can’t 3D print that material,” says Dr Byrne. “Now we can shape and tune the aerogel to manipulate the size and distribution of the tunnels to make the ideal shape.” The pores of the aerogel can be manipulated based on the drying technique – for example, supercritical CO2 drying is used to obtain an aerogel in the form of nanospheres.

The aerogels are now being tested to optimise their mechanical properties. “We are now entering pilot-scale trials and look to be at commercial scale within 3 to 5 years with industry support.”

This unique method of recycling denim will also help contribute to minimising textile waste, says Dr Byrne. “Textile waste is a global challenge with significant environmental implications, and we’ve been working for more than four years to address this problem with a viable textile recycling solution,” she said.

Textile recycling involves the use of chemicals, which can be both expensive and environmentally unfriendly. “We use environmentally-friendly chemicals, and by upcycling our approach to create a more advanced material we can address the limitations affecting other less cost-effective methods,” says Dr Byrne.

For more information, visit the Deakin Institute for Frontier Materials and the ARC Research Hub for Future Fibres.

– Larissa Fedunik

luxury watch

Luxury watch brand partners with nanotech

Featured image above: Christophe Hoppe with his new Bauselite luxury watch casing. Credit: Flinders University/Bausele.

In 2015, Bausele became the first Australian luxury watch brand to be invited to Baselworld in Switzerland – the world’s largest and most prestigious luxury watch and jewellery expo. Its success is, in part, thanks to a partnership with nanotechnologists at Flinders University and a unique new material called Bauselite.

Founded by Swiss-born Sydneysider Christophe Hoppe, Bausele Australia bills itself as the first “Swiss-made, Australian-designed” watch company. 

The name is an acronym for Beyond Australian Elements. Each watch has part of the Australian landscape embedded in its crown, or manual winding mechanism, such as red earth from the outback, beach sand or bits of opal.

But what makes the luxury watches unique is an innovative material called Bauselite developed in partnership with Flinders University’s Centre of NanoScale Science and Technology in Adelaide. An advanced ceramic nanotechnology, Bauselite is featured in Bausele’s Terra Australis watch, enabling design elements not found in its competitors.

NanoConnect program fosters industry partnership

Flinders University coordinates NanoConnect, a collaborative research program supported by the South Australian Government, which provides a low-risk pathway for companies to access university equipment and expertise.

It was through this program that Hoppe met nanotechnologist Professor David Lewis, and his colleagues Dr Jonathan Campbell and Dr Andrew Block.

“There were a lot of high IQs around that table, except for me,” jokes Hoppe about their first meeting.

After some preliminary discussions, the Flinders team set about researching the luxury watch industry and identified several areas for innovation. The one they focused on with Hoppe was around the manufacture of casings.

Apart from the face, the case is the most prominent feature on a watch head: it needs to be visually appealing but also lightweight and strong, says Hoppe, who is also Bausele’s chief designer.

The researchers suggested ceramics might be suitable. Conventional ceramics require casting, where a powder slurry is injected into a mould and heated in an oven. The process is suitable for high-volume manufacturing, but the end product is often hampered by small imperfections or deformities. This can cause components to break, resulting in wasted material, time and money. It can also make the material incompatible with complex designs, such as those featured in the Terra Australis.

New material offers ‘competitive edge’

Using a new technique, the Flinders team invented a unique, lightweight ceramic-like material that can be produced in small batches via a non-casting process, which helps eliminate defects found in conventional ceramics. They named the high-performance material Bauselite.

“Bauselite is strong, very light and, because of the way it is made, avoids many of the traps common with conventional ceramics,” explains Lewis.

The new material allows holes to be drilled more precisely, which is an important feature in watchmaking. “It means we can make bolder, more adventurous designs, which can give us a competitive advantage,” Hoppe says.

Bauselite can also be tailored to meet specific colour, shape and texture requirements. “This is a major selling point,” Hoppe says. “Watch cases usually have a shiny, stainless steel-like finish, but the Bauselite looks like a dark textured rock.”

Bauselite made its luxury watch debut in Bausele’s Terra Australis range. The ceramic nanotechnology and the watch captured the attention of several established brands when it was featured at Baselworld.

Advanced manufacturing hub in Australia

Hoppe and the Flinders University team are currently working on the development of new materials and features.

Together they have established a joint venture company called Australian Advanced Manufacturing to manufacture bauselite.  A range of other precision watch components could be in the pipeline.

The team hopes to become a ‘centre of excellence’ for watchmaking in Australia, supplying components to international luxury watchmaking brands.

But the priority is for the advanced manufacturing hub to begin making Bausele watches onshore: “I’ve seen what Europe is good at when it comes to creating luxury goods, and what makes it really special is when people control the whole process from beginning to end,” says Hoppe. “This is what we want to do. We’ll start with one component now, but we’ll begin to manufacture others.”

Hoppe hopes the hub will be a place where students can develop similar, high-performance materials, which could find applications across a range of industries, from aerospace to medicine for bone and joint reconstructions.

– Myles Gough

This article was first published by Australia Unlimited on 10 November 2016. Read the original article here