Ceramic capacitors with upper operating temperatures far beyond 200°C are essential for high‐temperature electronics used in deep oil drilling, aviation, automotive industry and so on. Recent advances in existing lead‐free dielectrics for potential high‐temperature capacitor applications are reviewed and grouped into three categories according to the parent component of the solid solution. Their desirable temperature stabilities were summarised comprehensively. However, there are still some limitations in the current research, such as achieving low loss in a wide temperature range and maintaining stable dielectric properties with different frequencies or at different voltages. Furthermore, the successful implementation of multilayer ceramic capacitors is one of the biggest challenges, which will have far‐reaching impacts on the realisation of high‐temperature capacitor application in the future.

With the rapid development of wearable devices, a highly sensitive flexible piezoelectric sensor shows tremendous potential for future demands. Here, we report a novel lead-free flexible piezoelectric sensor fabricated by a composite with chain-distributed (Ba_0.85Ca_0.15)(Ti_0.90Zr_0.10)O₃ (BCZT) particles in a polydimethylsiloxane (PDMS) matrix. The BCZT particles were prepared by a conventional solid oxide process and then dispersed in PDMS oriented by the application of a dielectrophoretic alignment field. The fabricated aligned flexible composite with 8 vol% BCZT addition had a high open circuit voltage of 28.8 V (peak-to-peak), which was nearly twice as high as that of the randomly dispersed composite. This new mechanically reinforced flexible piezoelectric composite was demonstrated to resolve the problems of the weak stress transfer to piezoelectric elements and the poor dispersion of fillers in the polymer matrix. The 8 vol% BCZT/PDMS composite was incorporated into a flexible piezoelectric touch sensor, which possesses excellent sensitivity in a wide pressure range and an extraordinary cycling stability. These results indicate that the fabricated flexible piezoelectric sensor has great potential in the wireless sensor network and wearable electronic fields.