From Triboelectric Nanogenerator to Hybrid Energy Harvesters: A Review on the Integration Strategy toward High Efficiency and Multifunctionality

The rapid development of smart devices and electronic products puts forward higher requirements for power supply components. As a promising solution, hybrid energy harvesters that are based on a triboelectric nanogenerator (HEHTNG) show advantages of both high energy harvesting efficiency and multifunctionality. Aiming to systematically elaborate the latest research progress of a HEHTNG, this review starts by introducing its working principle with a focus on the combination of triboelectric nanogenerators with various other energy harvesters, such as piezoelectric nanogenerators, thermoelectric/pyroelectric nanogenerators, solar cells, and electromagnetic nanogenerators. While the performance improvement and integration strategies of HEHTNG toward environmental energy harvesting are emphasized, the latest applications of HEHTNGs as multifunctional sensors in human health detection are also illustrated. Finally, we discuss the main challenges and prospects of HEHTNGs, hoping that this work can provide a clear direction for the future development of intelligent energy harvesting systems for the Internet of Things.