Hybrid nonlinear generator broadens low-speed wind energy harvesting for self-powered devices

Researchers have developed a nonlinear galloping-driven triboelectric-electromagnetic hybrid generator for harvesting low-speed wind energy, offering a new route toward self-powered sensors and distributed energy devices that can operate under weak and fluctuating airflow. The system, referred to as NG-TEHG, combines triboelectric and electromagnetic conversion with a nonlinear galloping structure, and the results suggest that this hybrid design can work over a relatively wide wind-speed range while producing enough power to support practical electronics such as wireless sensing nodes.

Low-speed wind is abundant in many natural and built environments, but it is difficult to use efficiently because the available kinetic energy is weak and often highly variable. That challenge is especially important for self-powered systems, where the goal is not large-scale electricity generation but dependable local power for low-energy electronics, sensors, or Internet of Things devices. Triboelectric nanogenerators, or TENGs, have attracted attention in this area because they can deliver high electrical output, are comparatively low cost, and can be designed in flexible structural forms. When paired with flow-induced vibration, they become particularly promising for harvesting wind energy that would otherwise be too weak or irregular for conventional approaches.

The new study addresses a common limitation in small-scale wind energy harvesting: narrow operating bandwidth. Many devices work efficiently only in a limited range of wind speeds, which reduces their usefulness in realistic outdoor conditions. To overcome that limitation, the researchers designed a nonlinear galloping-driven triboelectric-electromagnetic hybrid generator that can adapt to a broader range of flow conditions. In this system, the dynamics of a bluff body undergoing galloping are coupled with both triboelectric and electromagnetic energy conversion, enabling the device to make use of aeroelastic motion more effectively.

A key contribution of the paper is its quantitative analysis of the nonlinear coupling between the TENG and bluff-body galloping dynamics. Rather than treating the mechanical motion and electrical output as loosely connected, the researchers examined how nonlinear structural behavior and material choices jointly affect performance. This matters because galloping-based energy harvesters depend strongly on dynamic response. If the coupling is not well understood, the device may either fail to start at low wind speeds or lose efficiency over much of its usable range. By tuning both structure and material properties, the team sought to widen the operational window and improve the total harvested energy.

According to the article, the NG-TEHG operated effectively across a wind speed range of 2.29 to 7.80 m/s, demonstrating wideband low-speed wind energy harvesting. Experimental results showed a peak output power of 10 mW and an RMS power of 3.34 mW at a wind speed of 4.74 m/s. These figures are meaningful because they place the device beyond proof-of-concept novelty and into the range of practical low-power supply. The paper also emphasizes that nonlinear structural and material tuning were central to this performance, suggesting that the broad operating range is not incidental but is instead a deliberate consequence of the device design.

The practical demonstrations further strengthen the significance of the work. The researchers report that the generator was able to power LEDs and continuously drive a wireless temperature sensing node. That is an important milestone for small wind-energy harvesters, because a device that can directly support wireless sensing begins to approach real deployment scenarios. In distributed environmental monitoring, infrastructure sensing, or remote low-power electronics, the ability to harvest weak ambient wind and immediately support sensing or communication functions could reduce the need for batteries or frequent maintenance.

The study also speaks to a broader design strategy in energy harvesting: hybridization. Triboelectric generators and electromagnetic generators each have different strengths, and combining them in one nonlinear galloping system creates a more versatile energy-conversion architecture. Instead of relying on a single mechanism, the hybrid approach broadens the usable response of the system and improves adaptability to changing wind conditions. That is particularly relevant in real-world settings, where airflows are intermittent, multidirectional, and often far from ideal laboratory conditions.

Further work will still be needed to understand long-term durability, environmental stability, and how well the device performs under more complex field conditions. But the study provides a compelling demonstration that low-speed wind energy harvesting can be made both wider in operating range and more practically useful through nonlinear coupling and hybrid conversion design. For self-powered sensing and future distributed IoT systems, that could make weak ambient wind a more realistic and reliable energy source.

Reference

Author:

Xilong Kang ¹, Pengbo Li ¹, Yawei Wang ², Renyun Zhang ³, Yizhou Li ², Yupei Jian ⁴, Quanke Su ⁵, Guobiao Hu ², Junlei Wang ¹

Title of original paper:

A Nonlinear Galloping-Driven Triboelectric-Electromagnetic Hybrid Generator for Low-Speed Wind Energy Harvesting

Article link:

https://www.sciencedirect.com/science/article/pii/S2773153725001136

Journal:

Green Energy and Intelligent Transportation

DOI:

10.1016/j.geits.2025.100363

Affiliations:

1 School of Mechanical and Power Engineering, Zhengzhou University, Zhengzhou 450001, China

2 Thrust of the Internet of Things, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou 511400, China

3 Department of Natural Sciences, Mid Sweden University, Holmgatan 10, SE85170, Sundsvall, Sweden

4 School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China

5 Thrust of Intelligent Transportation, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou 511400, China