Effect of ZnS:Cu powder content on the mechanoluminescence intensity of stretchable elastomer composite for wearable device applications

Although wearable devices have attracted significant attention for multiple applications, most devices involve the conversion of electrical energy into a specific function. Owing to the ability of mechanoluminescence materials to emit light with mechanical stimuli, they can be considered as a potentially more efficient and versatile alternative wearable device that can function without electrical energy conversion. Composites of polydimethylsiloxane elastomers and ZnS:Cu powders possess ideal mechanoluminescence behaviors and stretching capabilities for wearable applications. Several studies have been conducted on their application; however, their luminescence intensity remains inadequate for further application. In addition, the effect of the particle volumetric content has not been thoroughly characterized. This mechanoluminescence characterization study found that by increasing the particle volumetric content up to 30%, the luminescence intensity significantly increased without affecting the stretchability of the composite. Further experiments and simulations were performed to investigate the relationship between the interparticle distance and its mechanoluminescence mechanism.