Shahkara’s talons are out-of-this-world tough. I’m not talking metal, but heavy duty titanium. As tough as the teeth of a lungfish or garfish.
A garfish, you say? Let me rewind…
When I first created my heart-devouring princess, I spent a lot of time researching her tougher-than-steel talons. They had to be strong, but flexible. After all, she ejects them from the flesh beneath her knuckles. Diamond is one of the hardest substances in the world, but I ditched the idea of diamond talons for something a little more realistic. Instead, I imagine her talons being a combination of dentine, cementum and enamel.
And why not? Recently, I heard that lungfish and garfish tooth enamel is being used as the springboard for creating a lighter material for aircrafts and other vehicles.
Queensland University of Technology (QUT) physics researcher Professor John Barry said teeth in different animals had been adapted or ‘engineered’ for various purposes in the past. “As engineering materials,” Prof Barry said, “teeth are composite materials with properties much superior to any existing synthetic composite.”
Prof Barry started studying lungfish because they are an ancient animal – he thought the lungfish tooth structure would be much simpler than modern animals that had undergone far more evolutionary changes.
“We were surprised to find the lungfish has a complex tooth microstructure – not simple at all. We are also studying garfish because they have hard-wearing teeth and we want to know how they manage that.”
Teeth are composed 95 per cent by weight of the mineral, hydroxyapatite, which on its own is very weak but when used by a living system is tough and durable.
Professor Barry is studying the tooth structure at three levels to model its strength in different situations and assess potential uses as a new material.
“The dentine’s crystals have various shapes and surface habits so I am looking at the way the crystals are arranged in different bundles and also how the tooth surface is arranged to cut, crush or grind food,” he said.
New materials of the past have have often been inspired by nature. Engineers invented fibreglass while trying to imitate the properties of wood, while velcro was based on the seed burrs that stick to clothing.
Prof Barry said copying some of the structures in teeth might lead to the creation of composites which could be used more widely in cars and aircraft, for example.
At present, carbon fibre composites are the best option available, but while they are very strong ‘along the grain’, they are very weak ‘across the grain’, making their uses limited.
“If general-use composites can be developed it will be possible to make cars and aircraft that are lighter and more fuel efficient,” Prof Barry said.
It sounds like I’m closer to finding a formula for Shahkara’s talons than ever before? But then again, maybe I don’t have to worry about composites like QUT, and just focus on the ride…
For more information about Prof Barry’s research, visit www.qut.edu.au