Thin-film triboluminescing ZnS:Mn coatings for impact load detection on polymeric substrates

Manganese doped Zinc sulfide (ZnS:Mn) is one of the brightest mechanoluminescent materials with an emitted peak wavelength of 590nm. ZnS:Mn has been shown to outperform other triboluminescing materials by detecting impact energy differences as low as 0.4 J. Previously, we have shown that the luminescent behavior (photo and tribo) of ZnS:Mn powder has not been discernibly affected by incorporating the particles into a polymer matrix, specifically, Sylgard 184. Here, we continue this work by exploring the sensitivity range and stability of ZnS:Mn thin films on two different substrates, namely silica-based aerogels and RTV 655. The motivation behind this work is to assess the feasibility of ZnS:Mn thin films as impact load detection tools, without susbtrate alteration of the mechanical properties of the underlying susbtrates. The investigation includes a systematic assessment of load tolerance and detection as a function of layer thickness and particle concentration.