Designing Ratiometric Mechanoluminescence via Threshold Manipulation in Sandwich Structures

Abstract The rapid development of mechanoluminescence (ML)‐based stress‐sensing has drawn wide concern for real‐time stress‐visualized detection. While the traditional ML‐intensity‐dependent stress‐sensing is challenged in terms of reliability and stress‐sensing visualization, ratiometric ML featured with stress‐dependent ML color variation provides an alternative solution. Herein, a strategy based on the manipulation of initial ML threshold of the individual phosphor via the flexible sandwich structure to realize ratiometric ML has been proposed. The two independent ML materials with different stress‐sensitivity can be incorporated into a sandwich structure to construct ratiometric ML, where the stress‐dependent ML color variation can be feasibly modified by means of judicious adjustment of sandwich structure. This strategy offers a versatile and convenient design solution for ratiometric ML aiming at stress‐visualized quantitative analysis.