Australasian Science: Australia's authority on science since 1938

A Time To Dance

By Stephen Luntz

Joel Miller is seeking to create better bone implants, and turned his PhD into a competition-winning dance.

University of Western Australia PhD student Joel Miller is the 2011 winner of the Dance Your PhD competition sponsored by Science. With his victory he completed an unprecedented trifecta for Australian science, along with Prof Brian Schmidt’s Nobel Prize and two Ig Nobel prizes (AS, December 2011, p.36–37; p.45).

Thesis-dancing prowess may never gain the same status as a Nobel, but Miller is on the way to catching the Igs after logging more than 100,000 views on the website where he uploaded Microstructure–Property Relationships in Ti2448 Components Produced by Selective Laser Melting: A Love Story – and many more views on media website worldwide.

Miller is just over 1 year into his thesis, and says that winning the prize has been very motivating. Moreover, the award came with a trip to the Technology, Entertainment and Design conference in Brussels, which enabled sidetrips to a major conference to meet world leaders in the field.

The video explores Miller’s efforts to build better bone implants. “Typically hip and knee replacements last for around 15 years before they need replacing,” Miller says. Bone needs to experience pressure and stretching or it starts to decay. Overly rigid titanium implants do not allow this, and eventually the bone around the implant diminishes to the point where the metal comes loose.

“What we’re really trying to do is create a sustainable relationship between metal and bone,” Miller says. “So, looked at that way, the idea of a love story looks obvious.”

Miller had heard of the competition, but decided to enter when his girlfriend Trish Wood suggested it. Wood is a contemporary dancer in Sydney, and Miller spent a week on holiday with her trying to come up with ideas. He says his original plans were too complex, and much of the filming had to be done after the holiday was over since it took him most of the allotted time to come up with a suitably simple concept.

Lacking a video camera, Miller decided that rather than trying to borrow one he would take thousands of images with an SLR camera and use an editing program to stitch them together into stop-motion animation. He only managed to submit the result an hour before the deadline, and looking at some of the more conventional dance routines already posted “wasn’t sure the judges would even recognise it as dance”.

“At room temperature pure titanium atoms align in a certain crystalline structure, known as alpha titanium,” Miller says. “It is strong but reasonably stiff.” A second beta titanium form can be produced at high temperatures and is suitably elastic, but it suffers fatigue. Miller is attempting to find the ideal combination of the two forms.

The process requires heating the metal until the beta form emerges, stabilising it and cooling to room temperature. The beta titanium is then heated to around 400°C, at which point some alpha titanium re-emerges.

The other aspect of Miller’s thesis, also performed in the video, involves using selective laser melting to construct a highly porous scaffold onto which bone can lock.

Miller says selective laser melting opens the door to “taking a CAT scan or an MRI, importing the scan into a program and creating a part in CAD that will match the existing bone structure, so creating a component that is much more personalised”.

Miller says: “I always took apart my broken toys as a child. I got a lot of satisfaction out of it, and at high school chose the subjects that gave engineering as an option.”

Miller’s studied Engineering/Arts at the University of Western Australia, with majors in mechanical engineering and psychology. The two may seem disparate, but Miller realised that psychology could assist in producing industrial designs with user-appeal, as well as being important for engineering management.

“For my undergrad course I chose materials engineering units,” Miller says. “I found them fascinating. After completing undergrad I worked in industry for a few years as a product designer and the materials engineering background was very important.”

Miller’s creation the Petrol Allsaw, a heavy-duty version of the electric allsaw that can be used to cut a range of materials, featured on The New Inventors. It can substitute for both chainsaws and brick cutters, which Miller calls “the two most dangerous items you can use without a licence”. The Allsaw uses two reciprocating blades with tungsten carbide teeth and is “about the safest tool you can have. With traditional cutters the dust alone is dangerous.”

Miller returned to university determined to work in either renewable energy or biomechanics, the areas he thought would help people the most, but found his calling in implants. The world may never know if there is a dance concept in solar panel design.