Abstract: A speaker device is provided. The speaker device comprising: a device body having: a top surface, a reflecting surface extending at least partially downwardly from an exterior edge of the top surface, at least one wall at least partially overlapping with the reflecting surface, an aperture being defined between the exterior edge of the top surface and a top edge of the at least one wall, a light source disposed in an interior of the device body, and a lightguide disposed in the interior of the device body, the lightguide extending at least partially between the light source and the aperture; and the reflecting surface, the light source, the lightguide, and the at least one wall being arranged such that light emitted by the light source: travels through the lightguide to be incident on the reflective surface; reflects off the reflecting surface; and exits the speaker device through the aperture.

Abstract: Disclosed are embodiments of an antiferroelectric (AFE) ceramic. The AFE ceramic includes a PbZrO3-based composition. The AFE ceramic has a charge-discharge energy efficiency of at least 96%, and the AFE ceramic has a recoverable energy density of at least 2.8 J/cm3 at a peak field of at least 200 kV/cm. Embodiments of a method of identifying potential AFE ceramic compositions having high energy efficiency and recoverable energy density are also disclosed.

Abstract: A lead zirconate-based antiferroelectric material is provided that includes lithium and bismuth substitutions for lead on the perovskite crystal structure. The lithium and bismuth are provided at an atomic ratio of 1:1, and the lead may substituted with lithium and bismuth up to 16 at %. The modified composition provides increased energy efficiency, increased dielectric breakdown strength, and lower sintering temperature. The modified composition is suitable for use as a capacitor having high power density and energy density.

Abstract: A preferred piezoelectric ceramic material is a BiFeO3—PbZrO3—PbTiO3 ternary solid solution wherein proportions of the constituent perovskite metal oxides are selected so that the material exhibits relatively high Curie temperatures above 380° C. and useful piezoelectric properties.

Abstract: A preferred piezoelectric ceramic material is a BiFeO3—PbZrO3—PbTiO3 ternary solid solution wherein proportions of the constituent perovskite metal oxides are selected so that the material exhibits relatively high Curie temperatures above 380° C. and useful piezoelectric properties.