Piezoelectric-Triboelectric Hybrid Nanogenerator for Energy Harvesting and Self-Powered Sensing Applications.

In the contemporary era, self-powered sensors have gained significant attention, particularly in the domains of wearable devices, flexible electronics, healthcare monitoring devices, and the Internet of Things (IoT). Among the most promising technologies for mechanical energy harvesting are piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs), both of which convert ambient mechanical energy into electrical energy. However, the electrical output from either PENGs or TENGs alone is often insufficient to meet the power requirements of electronic devices. To address this limitation, the integration of piezoelectric and triboelectric effects into a single system has led to the emergence of piezoelectric-triboelectric hybrid nanogenerators (PT-HNGs). These hybrid systems represent a new class of energy harvesting devices capable of significantly enhancing energy conversion efficiency and output performance. This review provides a comprehensive overview of recent progress in developing PT-HNGs, focusing on their underlying mechanisms, structural designs, coupling effects, performance optimization strategies, and diverse application potentials. It highlights the hybrid system's unique synergy and real-world applicability, aiming to fill a critical gap in the literature. In addition, the review discusses the existing challenges, future directions, and prospects for the commercialization of PT-HNG technology.