Breaking the screen of your smartphone by letting is slip away from your hands or accidentally sitting down on the damn thing while it’s still in your pocket is a prevalent modern annoyance that could soon go extinct due to the efforts of an international team of researchers led by Erkka Frankberg from Tampere University and Lucile Joly-Pottuz from the University of Lyon.
In their research, the team has found that films of amorphous (glassy) aluminium oxide can be easily stretched and bent at room temperature without snapping or shattering, which might lead to much more durable (and less irritating) electronics in the future.
“Almost all conventional glasses are based on silica – silicon and oxygen. But now we studied a glass that is composed of aluminium and oxygen,” said Erkka Frankberg. “Based on [our] results, it appears that actually there are glasses that can behave mechanically like a metal at room temperature. So, they can deform, stretch, bend and so forth without breaking – up to a certain point.”
Whereas the atomic structure of silica contains many gaps and defects which allow atoms to move more freely, the densely packed and nearly flawless structure of aluminium enables atoms to switch places with each other when exposed to mechanical stress, which leads to significantly greater plasticity.
The new material was achieved by breaking up aluminium oxide with a pulsed laser beam to form a purple-coloured plasma, and then rapidly cooling it down to prevent crystallisation.
“Designing oxide glasses with intrinsic ductility is an enormous and important challenge in the field of materials science, since their well-known brittleness hinders many functional and engineering applications,” said Morten Smedskjær from Aalborg University who was not involved in the project. “[This discovery] thus challenges our view about what is possible in this material family”.
Unfortunately, the complexity of making the new glass is such that unbreakable smartphones featuring this technology aren’t likely to appear on the market anytime soon. As the proof-of-concept moves on to more mature stages and the team learns more about the factors behind its high ductility, however, they may be able to “improve the processing of the material by manufacturing technologies to be more implementable on a larger scale”.