Super tough glass inspired by shells
Imagine a glass that doesn’t break, but merely bends on impact. This may seem too good to be true. But after studying mollusc shells, that is exactly what researchers at McGill university in Canada have come up with.
The glass is based on an idea taken from the inside of pearl shells. The nacre, which lines the inside of the shell, consists of tiny tablets which fit together tightly and which are both very strong and very tough.
By looking at the way that the edges of the mollusc shells work, the scientists were able to work out how to increase the toughness of glass sample slides. It turns out that the inside of shells (the shiny part of the shell) are covered with a huge number of 3D microscopic grooves.
Using lasers, the researchers were able to engrave similar grooves in wavy patterns onto borosilicate glass, a glass type commonly used for laboratory equipment. The results are amazing.
The cracks help the glass to absorb impact and in doing so, make it far less liable to breaking. So these patterns can help strengthen the glass. In fact, the technique used by the team at McGill made the glass 200 times as tough as usual.
A further modification was to fill in the tiny cracks with polyurethane, though this addition is not essential, as the cracks are all that is needed to stop the glass from shattering.
The next steps look exciting too. The scientists worked with glass mainly because it was readily accessible, and well-known to be brittle. In the future, they also plan to look at ceramics and polymer materials.
If you’re a regular reader, you may have noticed that we frequently mention biomimicry as a source of inspiration for many designers. There is very good reason for this: we really do have a lot to learn from nature. This super-tough glass is just one in a string of biomimicry-based advances in material innovation. There are certain to be many, many more.
Images via McGill university and commons licence.