The Indian Institute of Technology (IIT) Delhi has designed a device to generate electricity from raindrops, water streams, water drops, and even ocean waves using the 'triboelectric effect' and electrostatic induction. The electricity generated by the device, known as 'Liquid-solid Interface Triboelectric Nanogenerator', can be stored in batteries for further use.
The statement released by the IIT Delhi said, "The device consists of specially designed nanocomposite polymers and contact electrodes and able to generate a few m milliwatt (mW) power, which is enough to power small electronic devices like watches, radio frequency transmitters, digital thermometers, healthcare sensors and pedometers. If we look at the old methods, such as using the piezoelectric effect, it can generate significantly more electricity."
The Triboelectric Effect
"The triboelectric effect has been a very well-known phenomenon for a very long time, and in this effect, charges are generated when two surfaces are in friction. The best explanation for that is when we move the blankets or jackets and see sparkling lights with the same effect. Recently it has been carefully investigated as an alternative for energy harvesting," said Professor Neeraj Khare from the Department of Physics in IIT Delhi.
Professor Khare and his entire team at the Nanoscale Research Facility (NRF) IIT Delhi have been working on harvesting electrical energy from wasted mechanical vibrations using the triboelectric effect. The team has also filed an Indian patent on the various aspects of the use of ferroelectric polymer for harvesting mechanical energy, including the current device.
Ministry of Electronics and Information Technology (MEITY) and the Ministry of Science and Technology both have supported the research work under the NNetRa project. Researchers are also exploring the underlying mechanism of the electricity generated when the water drop comes in contact with the solid surface. It was found that saline water drops generate more electricity.