Pearl Coatings for Aircraft

New discoveries about the way that oysters form pearl in their shells has lead scientists to suggest that the future of aviation might be greatly affected by new lightweight and durable pearl-like coatings on various metallic surfaces.

Scientists from the University of Dayton Research Institute have been investigating new ways to coat metallic surfaces. Their research has revealed that, with enough study, it might be possible to use this biomimetic research to form coatings of pearl on various parts of aircraft, instead of the ceramics currently used. The Air Force currently uses ceramic coatings on various aircraft for a number of different purposes. These protective ceramic coatings are attached in a high-temperature, high-pressure environment and the process is long and hazardous. This new discovery could make ceramic coatings a thing of the past, with the new, pearl-like coatings being less hazardous to create as well as lighter and very durable.

The new research actually comes in the wake of the recent discovery that oysters use blood cells to deposit the crystals that form pearl and shell. Previously it was thought that oysters make use of the calcium carbonate in seawater to create their shells, but Dr. Andrew Mount’s most recent findings have now made this theory invalid. Building on this research, Doug Hansen, a senior research scientist at the University of Dayton Research Institute, has been studying how this information might be used to benefit humans.

Hansen and his wife Karoyln, who is also a UDRI senior research scientist, have taken live oysters and have been conducting experiments to demonstrate that pearly ceramic deposition can take place both inside and outside of the organisms. First, small pieces of metal were deposited into the oysters that then started to form pearl. Then blood cells were taken from the oysters and placed on metal. These then started to grow a shell on the surface of the metal. This remarkable research has been built on to demonstrate multilayer coatings on at least four different metals.

The Hansens’ ultimate goal is to better understand the process that is used by the cells to not only form but also deposit these crystals. It is hoped that with enough understanding of the process, scientists will be able to use this information to not only mimic the process, but also control the level of thickness and the placement of the coatings on various materials. The coatings are also being characterized in terms of corrosion resistance, adhesion and strength. If the research is successful it could usher in a whole new generation of aircraft.