Self‐Recoverable, Highly Repeatable, and Thermally Stable Mechanoluminescence for Dual‐Mode Information Storage and Photonic Skin Applications

Abstract Mechanically driven light generation is an intriguing phenomenon holding great promise in various fields. However, the existing mechanoluminescence (ML) materials always suffer from poor self‐recoverability, low repeatability, and environmental disturbance, severely hindering their practical applications. In this work, a self‐activating ML system based on interfacial triboelectrification is created by compositing the Ca 6 BaP 4 O 17 :0.02Ce 3+ powders into a flexible polydimethylsiloxane (PDMS) matrix. With no need for pre‐irradiation, the composite film emits self‐activating and self‐charging ML simultaneously in response to the rubbing or stretching stimuli. Accordingly, the Ca 6 BaP 4 O 17 :0.02Ce 3+ /PDMS exhibits desirable self‐recovery and repeatable ML performance, which could still be recorded (or observed by naked eyes) even after ca. 1000 stretching cycles with a fast self‐recovery period of < 0.1 s. Furthermore, the Ca 6 BaP 4 O 17 :0.02Ce 3+ /PDMS possesses good thermal stability in a temperature range from 298 to 473 K. The developed Ca 6 BaP 4 O 17 :0.02Ce 3+ /PDMS is applicable to various fields, and the dual‐mode information storage and photonic skin devices are created as representatives. Compared to the existing oxide‐based ML materials (the ML signal disappears after only several or tens of rapid mechanics cycles), this work breaks through the bottleneck issues on the self‐recoverability, repeatability, and thermal stability, which significantly advances the ML field.