The multilayered ceramic capacitor (MLCC) is a key component of electronic equipment, such as smartphones, portable PCs and electric vehicles, which contain a number of MLCCs. As MLCCs distribute and control the amount of current flowing through circuits, remove noise, and prevent malfunction, MLCCs play a key role in enabling electronic devices to have high performance, multi-functionality, and high integration. This review highlights the critical issues and recent progress in developing highly volumetric-efficient and high capacitance MLCCs from the viewpoint of designing a BaTiO₃-based dielectric layer. After a brief introduction of MLCCs and dielectric materials, we summarize the current issues in developing BaTiO₃-based dielectric materials for MLCCs with high performance and reliability and describe the strategies to optimize dielectric properties through nano/microstructure control, chemical modification and doping. Finally, we provide an outlook on the development and future application of MLCCs. It is anticipated that this review can serve as an overview and evaluation of state-of-the-art synthesis and design of BaTiO₃-based dielectric materials for MLCC applications.

Recent advances in flexible and stretchable electronics have led to a surge of electronic skin (e-skin)–based health monitoring platforms. Conventional wireless e-skins rely on rigid integrated circuit chips that compromise the overall flexibility and consume considerable power. Chip-less wireless e-skins based on inductor-capacitor resonators are limited to mechanical sensors with low sensitivities. We report a chip-less wireless e-skin based on surface acoustic wave sensors made of freestanding ultrathin single-crystalline piezoelectric gallium nitride membranes. Surface acoustic wave–based e-skin offers highly sensitive, low-power, and long-term sensing of strain, ultraviolet light, and ion concentrations in sweat. We demonstrate weeklong monitoring of pulse. These results present routes to inexpensive and versatile low-power, high-sensitivity platforms for wireless health monitoring devices.

In view of the increasing applications of nanocatalysis in chemical transformations, this article illustrates recent advances on the use of nanocatalysts for an important reduction reaction, the hydrogenation of nitroaromatics to significant aminoaromatics with aqueous NaBH₄ solution; the utility of mono- and multimetal nanocatalysts with special emphasis on heterogeneous nanocatalysts is included. A progressive trend on the applicability of nanocatalysts is also incorporated with large-scale application and their sustainable recyclization and reuse utilizing supported and magnetic nanocatalysts; representative methods for the synthesis of such reusable nanocatalysts are featured.