Characterization methods for mechanoluminescent materials

Mechanoluminescence (ML) is a unique luminescent phenomenon that converts mechanical energy into light energy. Recently, it has attracted the attention of many researchers due to its potential applications in visible stress sensing, wearable luminescent devices, self-powered electronic skin, and luminescent anti-counterfeiting. However, the absence of standardized testing methods and metrics for evaluating the performance of ML materials poses a hinderance to the development of ML. In this review, we focus on the ML testing methods, with an emphasis on the testing specimen, force application equipment and optical signal acquisition systems. Finally, we conclude with discussions on the future necessity and existing problems regarding the standardization of characterization methods for ML properties, aiming to provide a reference idea for the standardization of ML.