Energy focusing reinforced narrowband ultraviolet-B mechanoluminescence for bright-field stress visualization

Abstract

Real-time visualization of stress-sensing can be potentially realized using mechanoluminescence (ML) materials that are able to transform mechanical stimulates into luminescence. The unsatisfactory ML brightness, however, restricts such applications of ML materials mainly to dark-field scenarios. Thanks to the low UV proportion in the solar spectrum, a UV ML material may afford a suitable signal-to-noise ratio (SNR) to support stress-sensing in bright-field environments. Herein, ultraviolet-B (UVB) ML materials with visible-blind features have been developed for the first time to enable a bright-field visualization of stress-sensing. Specifically, an energy-focusing process has been applied via a sensitization strategy to reinforce the ML intensity in the UVB region at the cost of that in other regions, which helps achieving a better SNR for UVB ML materials. This work provides a new opportunity in terms of the application of ML materials in bright field environments.