Structural design and optimization techniques for the rotational triboelectric nanogenerators – An overview

Environmental issues and energy crises induced by the excessive consumption of fossil fuels, together with bottlenecks like resource dependence and pollution risks confronted by traditional battery technologies, have driven the innovation of sustainable energy technologies. Triboelectric nanogenerators (TENG), as an emerging energy harvesting technology, have gained prominence due to their superior adaptability to low-frequency mechanical energy. Rotational triboelectric nanogenerators (R-TENG), a core branch of TENGs, are specifically designed to capture rotational mechanical energy and to synchronously sense motion states. The output electrical signals of R-TENGs can also reflect the periodic position changes in motor drives, which can ensure reliable rotor position estimation and precise motor system control. Meanwhile, the energy harvested by R-TENGs can be utilized as a power source for subsequent modules such as conditioning circuits. This demonstrates the enormous potential of R-TENGs in fields including motor control and wind speed detection. In this paper, the basic principles and operation modes of R-TENGs are reviewed. The structural characteristics of three core types such as the contact-mode, contact-separation-mode, and non-contact-mode are analyzed in a categorized manner. Their application progress across multiple fields is summarized. Pathways for performance enhancement, including material innovation, structural optimization, and power management, are outlined. Finally, current challenges such as output stability and material durability, as well as future development trends, are discussed.