A low-cost triboelectric system developed at Nanyang Technological University (NTU) Singapore harnesses and stores energy from low velocity wind.

The system can produce a voltage of 3 V and generate electricity power of up to 290 μW when subjected to winds with a velocity as low as 2 m/second. This output is sufficient to power a commercial sensor that can then send acquired data to a mobile phone or a computer and offers the potential to replace batteries in powering LED lights and structural health monitoring sensors.

“Our research aims to tackle the lack of a small-scale energy harvester for more targeted functions, such asResearchers demonstrated how the device generates and stores electricity when exposed to low velocity winds in a wind tunnel. Source: NTU Singapore to power 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,” explained the researchers.

The 15 cm by 20 cm harvester is composed of a host cantilever beam, a stopper and a middle plate with one rotation degree of freedom. 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 and generates electricity due to the triboelectric-based conversion mechanism.

As reported in Mechanical Systems and Signal Processing, the device was demonstrated to power 40 LEDs consistently at a wind speed of 4 m/second. The harvester also triggered and powered a sensor device to transmit room temperature information to a mobile phone wirelessly. Excess charge was successfully stored to keep the system powered for an extended period in the absence of wind.