Intense and repeatable orange mechanoluminescence of Mn2+ activated CaGa4O7 for visualized mechanics sensing

Abstract

Because of the unique and attractive mechanics–optics conversion without additional energy consumption, mechanoluminescence (ML) has shown widespread prospects in visualized mechanics sensing. However, the current ML-based sensing technique mainly relies on short-wavelength materials, which limits its application range. In this work, a novel ML material, Mn²⁺-doped CaGa₄O₇ (CGOM), is synthesized, and the composite elastomer CGOM/polydimethylsiloxane (PDMS) exhibits an intense and repeatable orange ML with a relatively long wavelength range of 500–710 nm. The initial ML intensity of the CGOM/PDMS is about 2.8 times that of ZnS:Cu/PDMS under the same testing conditions, which makes its ML visible in ambient light. The ML mechanism conforms to the interfacial triboelectricity-induced electron bombardment model, based on which the repeatable ML is realized without a pre-charging process. In addition, the ML of the CGOM/PDMS shows good responsiveness to the applied friction and tensile parameters. Based on these features, the CGOM/PDMS is further applied to visualized mechanics sensing by simulating the organism and the competitive sports scenarios.