Ultrasonic wave induced mechanoluminescence and its application for photocatalysis as ubiquitous light source

For the purpose of mechanoluminescent (ML) ubiquitous light source, we focus on ultrasonic wave as non-destructive and non-invasive stimulation for bio-tissue. Actually we have investigated ultrasonic wave induced mechanoluminescence (USML) and successfully detected the mechanoluminescence response accompanied by the ultrasonic wave irradiation. The USML intensity depends on kinds of ML material, input intensity of ultrasonic wave and so on. The USML properties, such as sustainability, temperature dependence and input mechanical load dependence, were same as the ML properties shown in conventional ML test by using universal testing machine so far. Furthermore, though it was in primitive stage, we successfully detected degradation of methylene blue dye accompanied by US irradiation to mixture solution with visible light responding TiO2 photocatalyst and europium doped strontium aluminate (SAOE), and demonstrated the USML acted as the light source for a photo-activation of TiO2 photocatalyst for the first time.