Wind Speed Adaptive Triboelectric Nanogenerator with Low Start-up Wind Speed, Enhanced Durability and High Power Density via the Synergistic Mechanism of Magnetic and Centrifugal Forces for Intelligent Street Lamp System

Minimizing start-up wind speed, reducing material wear and enhancing power density are three pivotal concerns for the TENG for harvesting wind energy. Here, a wind speed adaptive triboelectric nanogenerator (WSA-TENG) via a synergistic mechanism of magnetic and centrifugal forces is proposed. Owing to this new mechanical synergistic mechanism, WSA-TENG can operate in non-contact mode at low wind speed and in soft contact mode at high wind speed. This is significantly different from the previously reported TENGs with dual-mode automatic switching mode. As a result, WSA-TENG simultaneously achieves low start-up wind speed (1.6 m/s), enhanced durability and high power density, which enables WSA-TENG ideal for wind energy harvesting in the actual environment. WSA-TENG can achieve the maximum peak power density of 64.2 mW·m^-2·m^-1s at 3.3 m/s wind speed. Moreover, it can maintain 99.4% of initial electrical output after continuous operation of 90,000 cycles. The demonstrations show that WSA-TENG can supply power to temperature/humidity sensor and transmitter to realize wireless real-time monitoring of temperature/humidity and realize wind speed monitoring through electrical signal analysis, which has great potential applications in intelligent street lamp system. This work provides a strategy for simultaneously lowing start-up wind speed, boosting durability and improving power density of TENG.