Empowering Flexible Electronics with Piezoelectric Nanogenerators: Breakthroughs from Energy Harvesting to Intelligent Sensing

Flexible sensing devices and energy storage systems with self-powered capabilities are propelling the rapid advancement of flexible electronics and wearable technologies. Piezoelectric nanogenerators (PENGs) present a compelling alternative to the constraints of conventional battery-powered systems, which suffer from limited capacity and short lifespans. By exploiting the piezoelectric effect, PENGs convert mechanical energy into electrical energy without the need for an external power source, producing electricity in response to mechanical stimuli, including vibration, pressure, and force. When integrated into flexible electronics and sensors, PENGs facilitate applications such as health monitoring, bionic electronic skin, and tactile sensing. Furthermore, PENGs can be combined with energy storage systems such as self-recharging supercapacitors and batteries, enhancing energy harvesting and conversion, while promoting sustainable energy utilization and ensuring a reliable power supply. This paper reviews recent advancements in PENGs, highlighting their theoretical foundation, structural design, and potential applications in sensors and energy storage systems, and discusses potential future directions for their continued advancement.