Physicists in Saga, Japan, deposited a film on a ceramic substrate that emitted strong visible light when it was mechanically stressed. The researchers from Saga University and the Kyushu National Industrial Research Institute suggested that the Mn-doped, crystalline ZnS skin will find applications in actuators and optical sensors to analyze moving parts without physical contact.

ZnS:Mn luminesces with a 585-nm peak and an intensity that is proportional to the stress. Further, the piezoluminescent response is reproducible, in contrast to the phenomena produced by similar materials, which emit once when they fracture. The team noted that the long-term stability of the effect should be tested.

The results of the study were published in the March 1 issue of Applied Physics Letters.