A new portable micro wind that exploits the triboelectric effect
(sustainabilityenvironment.com) – It may not be as powerful as classic three-bladed turbines, but the portable micro wind created by a group of scientists in Singapore takes wind exploitation to a new scale. New and very small. Researchers at Nanyang Technological University (NTU) have created a simple and affordable device capable of producing useful energy quantities by exploiting simple breezes.
The technology behind the project is not really new. The portable micro wind takes advantage of the so-called triboelectric effect, which consists of the transfer of charges between different materials when rubbed together. Thanks to friction, one of the two materials will tend to yield electrons and charge positively, the other will tend to acquire them and charge negatively, thus creating tension. A simple mechanism studied since ancient times (the first electrostatic machine dates back to 1660) and that has aroused in recent years a renewed interest in the world of energy research.
The triboelectric device of the NTU has a body in epoxy fiber, a highly resistant polymer, to which is attached a retainer made of copper, aluminum and Teflon. When the system is exposed to the wind, it starts vibrating, bringing the elements closer and further apart. And this causes the formation of posts. In laboratory tests, the device was shown to power 40 LEDs continuously at a wind speed of 4 meters per second. Not only that. It has shown that it can also store excess charges to maintain power even in the absence of wind.
“When exposed to winds with a speed of two meters per second – explain scientists – can produce a voltage of 3 volts and generate an electrical power of up to 290 microwatts, enough to power a commercial sensor and send data to a mobile phone or a computer“.
Measuring only 15 by 20 centimeters, it can be easily mounted on the sides of buildings and would be ideal for integration in urban environments, such as the outskirts of Singapore, where the average wind speed is less than 2.5 meters per second. The research was published in Mechanical Systems and Signal Processing.