This ‘wind harvester’ can convert the slightest breeze into electricity for small-scale gadgets

Researchers from Nanyang Technological University (NTU Singapore) have created a low-cost tool that can capture power from wind energy as gentle as a light breeze under the direction of Professor Yang Yaowen, Associate Chair of the School of Civil and Environmental Engineering.

As mentioned in the press release, this newly-developed device can produce a voltage of three volts and electrical power of up to 290 microwatts when exposed to winds with speeds as low as two meters per second (m/s). This is enough to power a commercial sensor device and allow it to transfer data to a mobile phone or computer.

The lightweight, durable gadget, known as a wind harvester, also directs any unused electricity to a battery so that it may be stored and used to power gadgets when there is no wind.

The findings were published in Mechanical Systems and Signal Processing's September issue.

The researchers claim that their creation has the potential to take the place of batteries in the powering of sensors for structural health monitoring and light-emitting diode (LED) lights.

These are used to monitor the structural health of metropolitan constructions like skyscrapers and bridges, warning engineers of problems like instabilities or physical damage.

Wind power has attracted extensive research attention

Professor Yang Yaowen, a structural engineer from NTU's School of Civil and Environmental Engineering (CEE), who led the project, said, "As a renewable and clean energy source, wind power generation has attracted extensive research attention. Our research aims to tackle the lack of a small-scale energy harvester for more targeted functions, such as powering smaller sensors and electronic devices."

"The device we developed also serves as a potential alternative to smaller lithium-ion batteries, as our wind harvester is self-sufficient and would only require occasional maintenance, and does not use heavy metals, which, if not disposed of properly, could cause environmental problems."

The industry has expressed interest in the idea. The NTU research team is also attempting to market its creation.

The study demonstrates NTU's dedication to reducing our impact on the environment, one of four grand challenges facing humanity that the University seeks to address through its NTU 2025 strategic plan. The innovation presented in the study could help reduce electronic waste and find alternative energy sources.

Abstract:

This paper presents a novel wind energy harvester utilizing galloping effect coupled with triboelectric-based energy conversion to convert the flow-induced structural vibration into electricity. The proposed harvester comprises a host cantilever beam, a stopper, and a middle plate with one rotation degree of freedom. The triboelectric layers and electrodes are placed in between the surface of the stopper and middle plate. A bluff body is fixed at the free end of the host beam to induce galloping vibration, which drives the middle plate to contact with the stopper periodically, thus generating electricity due to the triboelectric-based conversion mechanism. The proposed harvester can harness energy from wind velocity as low as 2 m/s depending on the selection of cantilever beams. A distributed coupled aero-electro-mechanical model is formulated to investigate the dynamic behavior of the harvester. The impact between the middle plate and stopper is found to have a significant influence on the energy generation performance of the harvester. Rigid impact could cause irregular and impulsive separation of contact surfaces, leading to sporadic voltage output. An optimal configuration is determined by selecting proper parameters of the stopper, bluff body, and gap distance in the design of the harvester. The proposed model shows good accuracy for modeling a moderate impact-engaged triboelectric harvester working on contact and separation mode. The fabricated harvester prototypes can produce a root mean square voltage of 12.8 V with a maximum power of 290 µW at wind velocity of 10 m/s. Even at low wind velocity, such as 6 m/s, the maximum power can reach up to 196 µW, demonstrating the promising energy scavenging capability of the proposed harvester.