SrAl ₂ O ₄ : Eu ²⁺ , Dy ³⁺ mechanoluminescent phosphor for potential bearings stress distribution imaging

Abstract Mechanoluminescence (ML) materials have shown broad application potentials in stress sensing and structural monitoring due to in situ, real‐time monitoring, and low trigger threshold. However, the accurate detection of stress distribution inside machinery still faces certain challenges. Based on a flexible ML film prepared by SrAl 2 O 4 : Eu 2+ , Dy 3+ phosphor and polydimethylsiloxane, this paper proposes a “stress difference” strategy to monitor the stress distribution inside the mechanical structure. By applying different loads and recording the linear relationship between ML intensity and the load, the local stress distribution in the engine bearing can be measured. By comparing the difference between I ML and I PersL , the specific stress distribution inside the machine is successfully inferred. This study provides new ideas for the application of ML materials in stress sensing, which may open up an innovative method for stress monitoring inside mechanical structures.