A new glass-ceramic that emits light in response to mechanical stress has been created by researchers, according to a report published in the July 2022 edition of Optical Materials Express commemorating the United Nations International Year of Glass 2022.

The property, known as mechanoluminescence (ML), could potentially be used to create a light source that is activated by mechanical stress. ML refers to the phenomenon of light being produced when a substance is subjected to external mechanical stimuli, such as grinding, rubbing or crushing. This process has drawn attention to its potential applications in pressure sensors, damage detections, bioimaging and lighting. According to the team of researchers, glass-ceramic could be used to monitor stress or fractures in buildings and other structures.

The glass ceramic is made from chromium-doped zinc gallate (ZGO) crystals embedded in a potassium germanate glass matrix. The crystals give the material its mechanoluminescent properties. However, they are small enough to not affect the transparency of the glass, according to the report.

The researchers decided to use glass-ceramics to create a more practical material. This is because mechanoluminescent powders are difficult to form into various shapes.

Glass-ceramics are a relatively new type of material that consists of a crystalline material embedded into a glass matrix. The crystals can be used to give these materials specific properties while the glass matrix allows them to be shaped with many of the same processes used for glass.

The researchers were able to create the mechanoluminescent glass-ceramic by developing a fast and stable crystallization process that allows the ZGO crystals to deposit similarly inside the glass after it has been shaped.

Now that the researchers have been able to demonstrate the material’s light-emitting properties, they want to exploit other features attributed to glass-ceramics, such as thermal, chemical and mechanical stability.