Arc-Shaped Triboelectric Nanogenerator Based on Rolling Structure for Harvesting Low-Frequency Water Wave Energy

Ocean occupies about 71% of the global surface area and contains 97% of the total water on the earth. Ocean waves are regarded as one of the most promising renewable energy sources, but it is quite difficult to harvest such low-quality and low-frequency energy due to the technology limitations of traditional electromagnetic generators. In this work, a type of arc-shaped triboelectric nanogenerator (AS-TENG) with internal rolling structure is designed to harvest low-frequency water wave energy. The freestanding roller with flexible surfaces can scroll freely with low friction along the arched track under external triggering, generating induced current between the complementary electrodes. The arc-shaped design facilitates the high-density integrating of multiple TENG units and effective packaging for potential large-scope applications. One AS-TENG can deliver an output power density of 5.47 W m(-3) under regular triggering, while a power density of 2.34 W m(-3) is achieved for an AS-TENG array under real water wave triggering of 1.2 Hz. Moreover, through harvesting water wave energy by the AS-TENG array, self-powered temperature sensing and wireless transmission systems have been successfully constructed. This work demonstrates huge application prospects of the AS-TENGs toward large-scale ocean blue energy harvesting and environmental monitoring.