Advances in magnetic-assisted triboelectric nanogenerators: structures, materials and self-sensing systems

Triboelectric nanogenerators (TENG), renowned for their remarkable capability to harness weak mechanical energy from the environment, have gained considerable attention owing to their cost-effectiveness, high output, and adaptability. This review provides a unique perspective by conducting a comprehensive and in-depth analysis of magnetically assisted TENGs that encompass structures, materials, and self-powered sensing systems. We systematically summarize the diverse functions of the magnetic assistance for TENGs, including system stiffness, components of the hybrid electromagnetic-triboelectric generator, transmission, and interaction forces. In the material domain, we review the incorporation of magnetic nano-composites materials, along with ferrofluid-based TENG and microstructure verification, which have also been summarized based on existing research. Furthermore, we delve into the research progress on physical quantity sensing and human-machine interface in magnetic-assisted TENGs. Our analysis highlights that magnetic assistance extends beyond the repulsive and suction forces under a magnetic field, thereby playing multifaceted roles in improving the output performance and environmental adaptability of the TENGs. Finally, we present the prevailing challenges and offer insights into the future trajectory of the magnetic-assisted TENGs development.