Researchers at the Indian Institute of Technology in Delhi (IIT-Delhi) have developed a device called the liquid-solid interface triboelectric nanogenerator. It can generate electricity from water drops, raindrops, water streams, and the ocean. The structure of the device consists of nanocomposite polymers and contact electrodes. The device can generate a few milliwatts (mw) of power, which is able to recharge small electric devices like watches, digital thermometers, radio frequency transmitters, healthcare sensors, and pedometers.
According to a news report, while comparing with the use of other effects such as the piezoelectric effect, the current device will be able to generate more electricity. The piezoelectric effect can generate an electric charge when a certain amount of mechanical stress is applied. But IIT-Delhi researchers have been working to generate electricity with the use of wasted mechanical vibration by using an effect named triboelectric effect, which derives and stores the energy. The researchers have demonstrated how the device produces electricity when water rolls over its surface. The device can also store the energy in batteries for further use.
The Ministry of Science and Technology and the Ministry of Electronics and Information Technology have supported the research under the Nanoelectronics Network for Research and Applications project (NNetRA). The group has filed an Indian patent on the various aspects of the use of ferroelectric polymer for harvesting mechanical energy, including the device. The researchers successfully incorporated nanostructures into a polymer matrix, which enhanced the film’s surface roughness, polarizability, and hydrophobicity, among other characteristics, as a result.
Due to the enhancement, the flexible film is used to fabricate the device where raindrops have to slide down and can generate electricity. The artificially-created rough surface allows to generate more charge and superhydrophobic properties of the solid surface help to roll the water drop without getting stick to the surface. Additionally, the IIT-Delhi research team has explored the mechanism by which the device generates electricity when the water drop comes in connection with the solid surface. While exploring the mechanism, the research team found that the saline water drops produce more electricity than freshwater.
Meanwhile, IIT-Delhi also recently set up a laboratory that will enable the measurement of the electrical performance of devices and circuits that are used in equipment like mobile phones, space satellites, and quantum computers. The lab it said will help researchers of IIT-Delhi as well as researchers from other institutions who are conducting research in the area of integrated electronic circuits and devices.
The Advanced Electrical Characterisation Laboratory was set up with an investment cost of IN₹170 million (US$2.3 million). The IIT-Delhi noted that the institution has significantly enhanced its research infrastructure in the last few years in the areas of nanofabrication, materials characterisation, testing, and prototype manufacturing. He added that this electrical characterisation facility is a welcome addition to the existing facilities. The laboratory in-charge explained that the institute is now equipped to perform various types of electrical measurements on a wide variety of packaged and on-wafer devices in a broad range of temperatures, with the highest levels of precision possibly anywhere in the world.