Mechanoluminescence of a thin composite layer obtained by incorporation of SrAl$_{2}$O$_{4}$ : (Eu$^{2+}$, Dy$^{3+}$) phosphor microparticles into a poly(methyl methacrylate) surface

A mechanoluminescent composite layer at the surface of poly(methyl methacrylate) (PMMA) was obtained by liquid-phase incorporation of SrAl$_{2}$O$_{4}$ : (Eu$^{2+}$, Dy$^{3+}$) phosphor microparticles into the polymer. The photoluminescence spectrum and kinetics of emission from the composite layer have been studied as dependent on the power density of exciting laser radiation pulses. The mechanoluminescence of the composite layer has been studied under the effect of short acoustic pulses and dynamic pressure of a solid stylus sliding over the composite layer surface. A possible mechanism of mechanoluminescence excitation is discussed. It is established that the obtained composite layer is characterized by high efficiency of the mechano-optical conversion and can be used for the detection and visualization of mechanical stresses.