A research team from the Okinawa Institute of Science and Technology Graduate University (OIST) in Japan has published findings in Chemical Science, successfully achieving mechanoluminescence in amorphous materials. This breakthrough brings new application possibilities to engineering materials and industrial safety fields.

Mechanoluminescence is a physical phenomenon where materials emit light under mechanical stimulation, traditionally observed only in rigid crystalline systems. Professor Julia Khusnutdinova, head of the Coordination Chemistry and Catalysis Unit at OIST, explained: "Crystals are prone to fracturing under mechanical stress. As the crystal structure is damaged and size decreases, their mechanoluminescence properties gradually weaken, significantly limiting practical applications. Amorphous materials can maintain longer-lasting luminescence characteristics, which drew our attention."

The research team prepared a series of amorphous compound thin films with photoluminescent properties and tested their mechanoluminescence effects through various methods, including contact-separation and friction. Experimental results showed that local electric fields generated by mechanical stimulation can excite luminescence in the material and surrounding gases. The researchers demonstrated non-destructive mechanoluminescence by stimulating the compounds through a protective plastic coating.

First author Dr. Ayumu Karimata stated: "The conventional view holds that crystal fracture is a key step in generating mechanoluminescence. We have proven this condition is not necessary. These findings open broad space for materials science, as they eliminate the need for complex crystal structures when manufacturing mechanoluminescent materials."

The new amorphous materials exhibit sustainable mechanoluminescence performance, providing new directions for developing novel sensors and smart materials. This material design approach is expected to drive the application and development of mechanoluminescence technology in a wider range of fields.