Critical to the new material’s success is its overall structure. Built from a microscopic lattice of crisscrossed struts, the ceramic has the ability to bend under crushing forces without snapping. Because of its flexibility the material readily returns to its original form, something that’s not characteristic of other fired clays.
"Ceramics have always been thought to be heavy and brittle," says Julia Greer, a professor of materials science at Caltech. “We're showing that in fact, they don't have to be either. This very clearly demonstrates that if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO to construct larger materials, you can obtain nearly any set of properties you want. You can create materials by design.”
To build their novel material researchers used two-photon lithography to draw a three-dimensional pattern into a polymer substrate. As parts of the polymer are lazed by the focused photon beam they harden, creating the complex structure that becomes the material’s body. Once hardened, a thin coating of alumina ceramic was sprayed onto the polymer superstructure and, after a drying period, the polymer was removed leaving only a hollow ceramic shell.
According to Greer, ceramic is not the only material that can be grafted onto a microscopic lattice-superstructure. Bone, metal, alloys and semiconductors could also be applied to a polymer superstructure to create new materials with a wide variety of applications.
Currently, Greer and her team are working on methods to scale-up production of their metamaterial. If a viable means of mass-production can be achieved, an explosion of organic and synthetic metamaterials may be only years away from their industrial debut. For now, only time will tell if this new ceramic will be the first in a string of wondrous new materials. Even if the ceramic is the only material of its type to make it out of the lab, its lighter-than-air and uncrushable characteristics are impressive to an otherworldly degree.
Source: Wyss Institute