Chew On This: Aircraft That Biomimic The Architecture Of A Tooth
You probably haven't spent a lot of time thinking about this, but exactly how do your teeth hold up to rock candy or peanut brittle or Brazil nuts? I could name a hundred food items which seem much harder than our teeth, yet if our teeth are healthy, we chew these foods without pain or loss of even a bit of enamel. Looking for an inspiration to build more crash resistant aircraft, mechanical engineers are looking at the architecture of the tooth.
Researchers at Tel Aviv University (TAU), along with engineering colleagues at the National Institute of Standards and Technology and George Washington University, tested hundreds of extracted teeth under varying degrees of pressure and showed how the teeth managed to stay in one piece because of their structures.
"Teeth are made from an extremely sophisticated composite material which reacts in an extraordinary way under pressure," says Prof. Chai of TAU. "Teeth exhibit graded mechanical properties and a cathedral-like geometry, and over time they develop a network of micro-cracks which help diffuse stress. This, and the tooth's built-in ability to heal the micro-cracks over time, prevents it from fracturing into large pieces when we eat hard food, like nuts."
The micro-cracks in the tooth structure provide release when something does crack the tooth, and this element is something that automotive and aviation engineers wish to biomimic. Additionally, teeth don't have a flat, layered structure as does the architecture of modern aircraft. Tooth architecture is more wavy and the fibers are arranged in matrices in several layers, providing innumerable cushions needed to prevent collapse of the tooth.The cathedral is a perfect image to suggest the layering in the tooth, although the spaces in the tooth are microscopic, unlike the cathedral's.
Researchers are not expecting to be able to produce self-healing aircraft any time soon, but by biomimicking the architecture of the tooth, they can develop lighter and more resilient aircraft.