How your Teeth are Helping Build Better Planes

What does a human, a walrus and a Tyrannosaurus Rex all have in common?

I bet your first guess was not the microscopic structure of their teeth enamel, but if somehow it was, you are exactly right!

This fun fact was discovered by Nicholas Kotov, a professor of chemical engineering at the University of Michigan College of Engineering. DARPA, the Defense Advanced Research Projects Agency, challenged researchers across the nation to develop a material that is strong and rigid, but can withstand frequent vibrations without cracking under the pressure. If you think about the stresses and demands on materials such as microchips in airplanes, or the electronic components in smart cars or smart devices, it is clear why such a material is in high demand.

When you analyze the structure and the strength capacity of most human made materials, you find that they are built to either be very strong and durable, or endure extensive vibrations, but not both. Metal, for example, is a very strong material, but it can develop tiny cracks that over time build up and eventually cause major structural failure. Rubber on the other hand, does not have the same problem. It is a material that can absorb just about any extreme pressure or vibration without cracking, but its strength is an lla time low. I do not think I would be boarding an entirely rubber made airplane any time soon.

As Kotov investigated he started buy turning to nature to find a design that combined both purposes, and he found one that did so beautifully, tooth enamel. Oddly enough, as he studied sample cells from creatures throughout time, as early as the tyrannosaurus rex, he found consistency in the microscopic design of their tooth enamel. Nature has found something that works and is sticking to it.

The structure of tooth enamel is designed to be strong enough to tear into food, while balancing the ability to handle decades of vibrations through chewing or even just walking around and being active. Its microscopic structure is designed one layer at a time. Each layer is made up of columns of strong ceramic crystals with soft organic proteins surrounding them. As any sort of pressure is put on a tooth, the columns will compress and bend, but the friction from the surrounding proteins absorbs the excess energy that could potentially break or crack the tooth’s structure. It is a fine, very detailed design that has achieved natural balance.

With Kotov’s discovery about the microscopic structure of tooth enamel, he began to realize the potential influence this could have in the world. A material made to reflect these properties could drastically improve the strength and safety of airplanes. No only the outer material, but the electronic components necessary for an airplane or rocket ship all undergo intense G force pressures and vibrations which put a lot of stress on the materials. These are not things you want to risk damaging either. A faux tooth enamel material could revolutionize the way these parts are created.

Kotov was able to achieve his goal of designing a fake tooth enamel from zinc oxide nanowires and a soft polymer material. This revolutionary combination was successful in imitating the balance of strength and endurance; however, it is a very time consuming creation process. After developing forty individually constructed layers, Kotov had just a single micrometer of material. While this is still a huge success, it will take time to construct a more marketable material with the same properties.

So, look forward to one day soon that you can find comfort in knowing that you will be flying in a giant tooth!