Synchronous Measurement of Temperature and Rotational Speed by Color‐Tunable Mechanoluminescent Material

ABSTRACT Monitoring temperature and rotational speed in extreme environments is a persistent challenge for conventional systems, which rely on separate electronic sensors and are prone to failure. To overcome this, we introduce a self‐power multimodal detection system for synchronous sensing of both parameters, enabled by a novel thermo‐sensitive color‐tunable mechanoluminescent material Cs 3 GdGe 3 O 9 :Tb 3+ , Eu 3+ , Na + . The maximum relative sensitivity is up to 4.5% K −1 , which is the most sensitive temperature‐sensing mechanoluminescent material to date. Crystallographic defect engineering facilitates energy transfer between rare‐earth ions, which enables the originally monochromatic mechanolumnescent material with temperature‐dependent variable colors. This work opens an avenue for the design of thermosensitive multi‐color mechanoluminescent materials and provides new strategies for integrated sensors.