Understanding Constitutive Relationship Between Mechanoluminescence of ZnS:Cu-PDMS and Strain

The research objective of this study is to deepen understanding about mechanoluminescent (ML) characteristics of the copper-doped zinc sulfide (ZnS:Cu)-based elastomeric composite, which is one of two functional building blocks of the mechano-luminescence-optoelectronic (MLO) composite, for advancing design of the MLO composite-based self-powered strain sensor. First, atomic structures of ZnS:Cu, which plays a pivotal role as a mechanical-radiant energy convertor is analyzed using Raman, Fourier-transform Infrared (FTIR), and photoluminescence (PL) spectroscopies under mechanical vibrations that trigger ML phenomena. Second, photometric analysis is performed to characterize ML light emission when the composite is subjected to tensile loading and unloading cycles. Last, constitutive relation between ML light intensity and strain is studied using two high-speed cameras and digital image correlation (DIC) technique.