Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade.

Sensor networks are essential for the development of the Internet of Things and the smart city. A general sensor, especially a mobile sensor, has to be driven by a power unit. When considering the high mobility, wide distribution and wireless operation of the sensors, their sustainable operation remains a critical challenge owing to the limited lifetime of an energy storage unit. In 2006, Wang proposed the concept of self-powered sensors/system, which harvests ambient energy to continuously drive a sensor without the use of an external power source. Based on the piezoelectric nanogenerator (PENG) and triboelectric nanogenerator (TENG), extensive studies have focused on self-powered sensors. TENG and PENG, as effective mechanical-to-electricity energy conversion technologies, have been used not only as power sources but also as active sensing devices in many application fields, including physical sensors, wearable devices, biomedical and health care, human–machine interface, chemical and environmental monitoring, smart traffic, smart cities, robotics, and fiber and fabric sensors. In this review, we systematically summarize the progress made by TENG and PENG in those application fields. A perspective will be given about the future of self-powered sensors.

Durability is a critical concern for triboelectric nanogenerators (TENGs) since it significantly impacts their output performance and stability. To address this issue, TENGs designed with rolling rods/balls have been developed to reduce surface wear. However, their line/point contact severely reduces the charge generation capability of triboelectric surfaces. Therefore, developing TENGs with both high output performance and low interface wear remains a significant challenge. Here, we propose a contact-sliding-separation motion strategy to realize a TENG with high output performance and remarkable durability. Compared to the contact-separation mode TENG, the contact-sliding-separation mode TENG (CSS-TENG) exhibits a 1000% increase in charge generation and a 35.6 times increase in output power. The CSS-TENG retains 99.8% of its output after 200 000 cycles, with an average triboelectric layer mass loss of 0.2 mg per 10 000 cycles with a diameter of 50 mm (<4% of the free-standing mode TENG). Furthermore, an integrated device is also designed, achieving a peak power density of 18.0 W m⁻³. Finally, after power management, the CSS-TENG generates a direct current of 3.7 mA, lighting ten 30 W lamps. This study addresses the limitations of the existing TENGs and offers a promising solution for developing high-performance TENGs.