High Strain-Rate Behavior Of Mechanoluminescent Material Dispersed In A Soft Polymer Matrix

Mechanoluminescence (ML) is the emission of light from a solid material in response to mechanical stimuli [1]. Mechanoluminescent materials are classified based on the types of stress activation required for luminescence behaviour. In this paper, we propose the study of light emission characteristics of an elastico-mechanoluminescent (EML) material dispersed in a soft polymer matrix, under high-strain compressive loading for a qualitative and quantitative testing of onsite strain. We developed a strain sensor by creating a composite material through the combination of a polydimethylsiloxane (PDMS) matrix structure and strontium aluminate, europium, and dysprosium doped (SAOED) crystals. SAOED crystals possess a strong luminescence behavior, which has led to their proliferation as a viable optical sensor. Composite materials were tested using a modified Kolsky bar and high-speed camera. The light-emitting characteristics of the SAOED crystals in response to mechanical stimuli allows for the quantification of stress–strain experienced by the composite material. The light intensity, which is measured by a complementary metal–oxide–semiconductor (CMOS) sensor in a high-speed digital camera, provides a quantitative measure of the strain-rate. Light-emitting characteristics of the EML material and the strain behavior of the material were studied.