Mechanoluminescence Recording Device Integrated with Photosensitive Material and Europium-Doped SrAl2O4

An accumulative and integrative mechanoluminescence recording system consisting of a mechanoluminescent (ML) material and a photosensitive material was successfully demonstrated. The ML material developed in our laboratory is the world's first light-emitting material for practical use with the application of stress in the elastic deformation region, and we can detect an area of concentrated stress on a measurement object using our ML material. For practical use of such a material, there are many information requirements, such as the size of the stress, its location, frequency, especially stress accumulation from the viewpoints of safety maintenance and reliability. In this system, the ML sheet (aluminum foil coated with ML paint including europium-doped strontium aluminate) was used as a stress detector and an emission unit and a commercial picture film was used as the accumulative and integrative photorecording materials, respectively. Using the ML recording system, the applied stress was successfully recorded onto the picture film accumulatively via the mechanoluminescence from the ML sheet, and the recorded intensity increased with increasing time and number of stress applications. (C) 2009 The Japan Society of Applied Physics