Ratiometric Mechanoluminescence of Double‐Activator Doped Phosphatic Phosphors: Color‐Resolved Visualization of Stress‐Sensing and Quantified Evaluation for Sensing Performance

Abstract Visualized self‐powering stress sensing can be realized via mechanoluminescence (ML) materials due to their ability to convert mechanical stimulate into optical signals. Traditional ML‐intensity‐based stress‐sensing is susceptible to errors caused by unpredictable measurement circumstances, which can be significantly improved by a recently developed ratiometric ML sensing strategy. Herein, a series of dual‐activator phosphatic materials are designed to realize ratiometric ML. The linear dependence of mechanoluminescence intensity ratio (MLIR) on the applied force leads to an obvious variation in ML emission color upon different applied stress, and therefore enables a color‐resolved visualization of stress‐sensing. Specifically, an evaluating system is established to quantify the stress‐sensing performance of ratiometric ML materials for the first time, which is considered to be an important step toward the practical application of ratiometric ML‐based stress‐sensing.