Zack Savitsky, a science journalist, reported on the research study on the "New Device Purifies Water with Static Electricity" in Inside Science, published on October 28, 2021. He studied this research from the scientific research paper "The water droplet with huge charge density excited by a triboelectric nanogenerator for water sterilisation" . The journalist states that, Guangqin Gu and his colleagues at Henan University in China have developed a device that uses the principle of a triboelectric nanogenerator, which harnesses static electricity to power a circuit that kills microorganisms in water. A process that could eventually help produce clean drinking water in remote areas. The team published their results in the journal Nanotechnology. Background to this research starts virtually 600 B.C., when warmed-over Greek philosophers noticed that without rubbing fur on amber, the fossilised sap attracted lightweight objects. Centuries later, scientists attributed the miracle to the triboelectric effect, or static electricity. Instead of using umber and feathers, Gu and his team exploit the effect with two thin discs of copper and polytetrafluoroethylene, the polymer used to stratify nonstick pans. In the self-powered system, a controlled stream of water rotates one disc at a unvarying rate, forcing repeated contact with the other disc; it looks like fingers brushing versus fan blades.
The electric field then destroys the cell membranes of bacteria in the water through a process called electroporation. The experiment tested water contaminated with Escherichia coli and Staphylococcus aureus, which can cause a variety of life-threatening diseases such as appendicitis and sepsis, respectively. Each strain of bacteria was completely inactivated in the water samples after two trips through the machine.
The main novelty of this research compared to other researchers is that the team from Henan has tried to use this technology to purify drinking water and has done so successfully without introducing contaminating ions or significantly changing the water's acidity. Even if the research can reduce the cost and increase the effectiveness of biological treatments, they will get great use and be a benefit to society. Still, there's one major holdup to the technology: the output performance isn't quite strong or reliable enough for real-world usage. While the device did kill the bacteria, it completely sterilised the water only at the sluggish rate of 0.31 millilitres per minute, which is over 45 minutes for a tablespoon. In addition to that, bacteria aren't the only contaminants lurking in water. Different systems would be needed to filter out sediments and chemicals.