An Investigation of the Mechanoluminescence of Composite Materials Based on a Polymer and a Phosphor Powder Excited by the Action of a Mechanical Striker, Stylus, and Laser Pulse

摘要

We studied the mechanoluminescence of composite materials based on polymethylmethacrylate and fine powder of Sr4Al14O25:(Eu2+,Dy3+) phosphor with a centrosymmetric crystal structure of microcrystals and fine powder of SrAl2O4:(Eu2+,Dy3+) phosphor with noncentrosymmetric structure. To study mechanoluminescence, a thin (similar to 250-300 mu m) layer of the composite material was deposited on the surface of a substrate transparent in the visible region of the spectrum. The mechanoluminescence of the composite layer was excited by the action of a mechanical striker, short laser pulses, or the dynamic pressure of a stylus sliding over the surface of the mechanoluminescent layer. The composite material based on a polymer and Sr4Al14O25:(Eu2+,Dy3+) powder with a centrosymmetric crystal lattice does not exhibit mechanoluminescence properties, while the composite material containing SrAl2O4:(Eu2+,Dy3+) exhibits pronounced mechanoluminescence. The excitation of mechanoluminescence in water begins at a much lower power density of laser pulses than in air. The resulting composite layer exhibits a high efficiency of "mechano-optical" conversion and can be used as sensor elements for sensors in mechatronic systems.