Achieve Mechanoluminescence And Investigation Its Performance And Physical Mechanism

Recently, mechanoluminescence materials have attracted considerable attention because of its potential application in stress sensor, defect monitor, artificial skin diagnosis and stress imaging, especially the elastic deformation luminescence is in the great advantage of the practical application due to its repeatability and non-destructive display. It is critical for the practical application to search a new mean to achieve mechanoluminescence and theoretical derivation, owing to the weak intensity of the current elastic deformation luminescence and the lack of the unified theory, as well as the single mean to achieve mechanoluminescence.(1) We deposited tantalum oxide film on a laminate structure composed of a Si substrate and a piezoelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-xPT) single crystal and achieved in situ modulation of the resistance and capacitance of the Ta2O5film. The modulation arises from the induced lattice strain in the Ta2O5film, which is induced by the electric-field-induced strain in the piezoelectric crystal. Under an external electric field of-2kV/cm, the longitudinal gauge factor of the Ta2O5film is-3300. A high-sensitivity mechanoluminescence sensor was fabricated on the basis of the laminate structure, achieving laminated elastic deformation luminescence. It is found that by adjusting the vibration strength or frequency applied the intensity of the elastic deformation luminescence can be obviously varied, which enables the distribution of different stress imaging and conjecture the intensity of the stress according to the varied luminescence. The laminated elastic deformation luminescence is more sensitive than the traditional ones.(2) The idea and successful practice of a tress sensor to sense mechanical stress by ZnS:Cu+ceramic through metal ion precipitation and sintering, has been realized, appearing reproducibly strong visible emission upon stressing. Corresponding to the increase and release of stress, respectively, two luminescent pulses were generated during one cycle of applied stress. The increase of the internal energy under compressive load is the main factor which lead to the strong reproducible and without attenuation mechanoluminesecence, inducing the trapped electrons released and the electron-hole emerged. The theoretical formula indicates that the intensity of luminescence is related with the rate of the stress changing, as well as the strength of the stress.Thirdly,(Bi0.5Na0.5)Ti03:Pr3+ceramic was fabricated by the conventional solid-state reaction method and high sintered method and the ferroelectric remanent polarization and strain can remarkably enhanced the photoluminescence intensity. It is also found that the remanent strain can increase the threshold of Pr3+concentration quenching. Our results reveal that the great potential to monitor the ferroelectric remanent polarization strength or strain through measuring the photoluminescence spectra.It has aroused widespread interest in the study on the mechanoluminescence materials, especially the elastic deformation luminescence, because of its potential applications in the smart stress and actuator devices. The route to achieve the mechanoluminescence through fabricating the laminated elastic deformation luminescence material in this study not only is simple, low cost, little pollution, but also emits high luminescence intensity. Mechanoluminescence sensors have great potential in smart stress-to-light devices, such as stress intelligent sensor (e.g. MEMS devices), the intelligent detection of industrial precision device defects, pulled muscle disease diagnosis, self-diagnosis of the artificial skin, smart aerospace devices and micro-crack detection.