Harmless Air Sterilization Could Potentially Kill Aerosolized COVID-19

Researchers are focusing efforts on developing antimicrobial technology that could effectively kill viruses such as COVID-19 and at the same time are harmless to humans and the environment. A study by KAIST research team revealed a technology that features electrosprayed water from a polymer micro-nozzle array, which leads to harmless air sterilization.

The electrosprayed microdroplets encapsulate reactive oxygen species such as hydroxyl radicals, superoxides that are known to have an antimicrobial function. The encapsulation prolongs the life of reactive oxygen species, which enables the droplets to perform their antimicrobial function effectively. Electrosprayed water generally operates under an electrical discharge condition, which can generate ozone. The inhalation of ozone is known to cause damage to the respiratory system of humans.

Another technical barrier for electrospraying is the low flow rate problem. Keeping this in mind, the team developed a dielectric polymer micro-nozzle array to perform the multiplexed electrospraying of water without electrical discharge. The high aspect ratio of the micro-nozzle and an in-plane extractor was proposed to concentrate the electric field at the tip of the micro-nozzle, which prevents the electrical discharge caused by the high surface tension of water. The water microdroplets were measured to be in the range of six to 10 μm and displayed an antimicrobial effect on Escherichia coli and Staphylococcus aureus.

Ref link: https://www.sciencedirect.com/science/article/abs/pii/S0032386120302421