Dynamic visualization of stress distribution by mechanoluminescence image

We report the realization of the dynamic image of stress distribution by developing a remarkably strong mechanoluminescence (ML) material of ${\mathrm{Sr}}_{\mathrm{0.975}}{\mathrm{Al}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3.985}}{\mathrm{:Eu}}_{\mathrm{0.01}},$ which can emit four orders of magnitude larger intensity than that of the reported strong ML material of quartz crystal. This ML material can be mixed in the target composite or coated on the surface to sense stress by emitting visible light. This method is applicable to the dynamic visualization of stress distribution in a solid not only in the atmosphere but also in an aqueous environment.