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The rapid development of wearable electronics highlights the urgence to develop the portable energy harvester with excellent output performance, comfortability, and sustainability. This work designs an electromagnetic walking energy harvester based on water turbine that can be embedded in shoes with good comfortability. Its working principle is that the walking generated pressure energy drives a miniature hydraulic turbine to output electricity. Experimental results show that an average power of 300 and 180 mW can be produced at heel and toe, respectively, when a man of 80 kg walks at a speed of 1.8 m s−1. This power output exceeds the piezoelectric, triboelectric, and electromagnetic walking energy harvesters reported in the past. Additionally, the simpler structure endows it better comfortability as compared with the electrostatic capacitances. Computational fluid dynamics simulations provide a further insight that the efficiency of turbine can reach 13.5% by optimizing parameters of blade number and outlet flow ratio. Finally, user real-time positioning and trajectory recording are successfully demonstrated via a wearable GPS means Global Positioning System module powered by the harvester. Due to the combination of high output performance, simple structure and low discomfort, the water turbine based walking energy harvester will provide a wide application potential in wearable devices. [ABSTRACT FROM AUTHOR]

Flexible capacitive pressure sensors have garnered significant attention in research areas such as electronic skin, wearable devices, medical diagnosis, physical health detection, and artificial intelligence due to their advantageous characteristics, including high sensitivity, flexibility, lightness, and easy integration. Over the past few years, the field of flexible capacitive pressure sensors has experienced notable advancements in materials, structural design, fabrication processes, and applications. This review aims to examine the different materials employed for sensor electrodes and dielectric layers, as well as the structural design of these sensors. Additionally, we delve into the diverse fabrication processes and techniques utilised, including electrode and dielectric layer fabrication, as well as weaving technology. Lastly, we explore the various applications of flexible capacitive pressure sensors, encompassing electronic skin, health monitoring device, electronic textiles, and structural health monitoring. [ABSTRACT FROM AUTHOR]

Lactic acid (LA) was originally employed as a cosolvent for solvothermal synthesis of LaPO4:Ce3+, Tb3+, Sm3+ nanocrystal phosphors, whose effect on crystal growth was revealed by the combined techniques XRD, FE-SEM and TEM. It was shown that LA not only remarkably restricted the intrinsic one-dimensional (1D) growth of hexagonal LaPO4 crystals along the [001] direction, resulting in a shape variation from microwires to nanoparticles, but also promoted crystallite growth. With more efficient Ce3+ → Tb3+ energy transfer resulting from larger crystallite size, the h-(La0.90Ce0.05Tb0.05)PO4 nanoparticles presented more intense and thermally stable green emission of Tb3+ as compared to the nanowires. Moreover, a series of (La0.93−xCe0.05TbxSm0.02)PO4 (x = 0–0.40) nanocrystals, with the emission color varying from blue to green and eventually to yellow, were successfully prepared through adjusting the concentration of Tb3+, in which the Tb3+ ion acted as an energy transfer bridge between Ce3+ and Sm3+. The mechanism of Ce3+ → Tb3+ → Sm3+ energy transfer was proposed, and the optimal Tb3+ content for Sm3+ emission was determined to be x = 0.20. The optimized (La0.73Ce0.05Tb0.20Sm0.02)PO4 phosphor exhibited good thermal stability for Sm3+ emission, whose activation energy for thermal quenching was found to be ∼0.33 eV. [ABSTRACT FROM AUTHOR]