# Self-Regulating Wind Speed Adaptive Mode Switching for Efficient Wind Energy Harvesting Towards Self-Powered Wireless Sensing

## TL;DR

A self-regulating wind energy harvester automatically adjusts to wind speed changes, efficiently powering wireless sensors for IoT systems.

## Contribution

A self-regulating TENG that automatically switches modes based on wind speed, achieving ultra-low startup wind speed and high durability.

## Key findings

- The SR-TENG achieves a start-up wind speed of 0.86 m/s and maintains performance across a wide wind speed range.
- The system reaches a peak open-circuit voltage of 140 V and a transferred charge of 300 nC at 375 rpm.
- The SR-TENG successfully powers a wireless sensor for real-time cloud data transmission.

## Abstract

Wind energy harvesting based on triboelectric nanogenerators (TENGs) is a promising solution for powering distributed Internet of Things (IoT) nodes, yet its practical efficiency and stability are often hindered by the fluctuating and unpredictable nature of wind. Here, we propose a self-regulating TENG (SR-TENG) that leverages the synergistic effects of centrifugal, elastic, and frictional forces to automatically switch between non-contact and contact modes based on wind speed. This configuration achieves an ultra-low start-up wind speed of 0.86 m/s, ensures sustainable high-performance output across a broad wind speed range, and exhibits excellent durability with no observable performance degradation during 23,000 s of continuous operation at 375 rpm. Systematic structural optimization enables the SR-TENG to reach a peak open-circuit voltage of 140 V, a short-circuit current of 12.5 μA, and a transferred charge of 300 nC at 375 rpm. When integrated with a customized power management circuit, the system delivers a 30.39-fold increase in effective output power at a 1 MΩ load and a 4-fold faster charging rate for a 10 μF capacitor. For practical validation, the harvested ambient wind energy successfully powers a wireless temperature-humidity sensor for real-time cloud data transmission. These results highlight that the SR-TENG holds great potential for advanced wind energy harvesting and self-powered sensing applications in distributed IoT systems.