This article reports a new phosphorescent material, CaZnOS:Cu, that exhibits two types of mechano-optical conversion: mechanical quenching and mechanoluminescence. An intense mechanical quenching of phosphorescence corresponding to mechanical stimuli can be achieved in CaZnOS:Cu within a short decay time period. Over time, it gradually changes to mechanoluminescence when a mechanical load is applied. We propose that the mechanical quenching and mechanoluminescence arise from the different roles of shallow and deep traps in CaZnOS:Cu. CaZnOS:Cu has promising applications in monitoring mechanical stress in industrial plants, structures, and living bodies.

Aluminum nitride (AlN) is one of piezoelectric materials, which are eagerly anticipated for use in microelectromechanical systems (MEMS) applications such as communication resonators, sensors, and energy harvesters. AlN is particularly excellent in generated voltage characteristics for the MEMS rather than oxide piezoelectric materials such as lead zirconium titanate Pb(Zr, Ti)O₃. However, it is necessary to improve the piezoelectric properties of AlN in order to advance the performance of the MEMS. We dramatically increased the piezoelectric coefficient d₃₃ of AlN films by simultaneously adding magnesium (Mg) and niobium (Nb). The d₃₃ of Mg_39.3Nb_25.0Al_35.7N is 22 pC/N, which is about four times that of AlN. The d₃₃ is increased by Mg and Nb simultaneous addition, and is not increased by Mg or Nb single addition. Interestingly, the Nb has multiple chemical states, and which are influenced by the Mg concentration.

A planar mixed-potential-type sensor using a yttria-stabilized zirconia and oxide-based sensing electrode (SE) was fabricated and the preliminary results on sensing characteristics were reported here. It was found that the sensor attached with exhibited good sensitivity and excellent selectivity to at under the wet condition ( ). While the cross sensitivities to the other examined gases were about or negligible, the sensitivity to was about . The of the sensor varied almost linearly with the concentration in the examined range of .