GS Paper - 3 (Energy)

Indian Institute of Technology (IIT)-Delhi researchers have designed a device that can generate electricity from water drops, raindrops, water streams, and ocean waves which can be stored in batteries for further use. The device has been developed using “Triboelectric Effect” and “Electrostatic Induction”.


  1. It is called “Liquid-solid Interface Triboelectric Nanogenerator”.
  2. The device has a very simple structure consisting of specially designed nanocomposite polymers and contact electrodes.
  3. It can generate a few Milliwatt (mW) power which is sufficient to power small electronic devices like watches, digital thermometers, radio frequency transmitters, healthcare sensors, pedometers.
  4. When compared to conventional methods, such as the use of the piezoelectric effect, the present device can generate significantly more electricity.
  5. Professor Neeraj Khare from the Department of Physics and his group at the Nanoscale Research Facility (NRF) have been working on harvesting electrical energy from wasted mechanical vibrations using the triboelectric effect.
  6. Researchers have filed an Indian patent on “the various aspects of the use of ferroelectric polymer for harvesting mechanical energy including the present device”.


  1. Triboelectric effect has been a known phenomenon for a long time, and in this effect, charges are generated when two surfaces are in friction.
  2. The best example we see are sparkling lights when we move the blankets/jackets.
  3. It is only lately that it has been extensively investigated as a practical alternative for energy harvesting.