The authors of the study believe that this phenomenon will help scientists better understand how bacteria and even viruses like SARS-CoV-2, which caused the COVID-19 pandemic, behave in aerosols. The study results were published in the Physical Chemistry Chemical Physics journal.
"Bacteria and viruses spread over long distances by aerosol. However, it’s impossible to focus a microscope on an aerosol drop to find out how these "travelling" microorganisms behave, while a drop cluster allows you to study them," Mikhail Nosonovsky, a senior researcher at the Microhydrodynamic Technologies Laboratory of UTMN Institute of Environmental and Agricultural Biology, and professor at the University of Wisconsin, said.
UTMN researchers have formed micro-droplet clusters by heating the water surface with a laser beam; clusters of several (no more than three dozen) drops caught the scientists’ attention. It turned out that the shape of such small clusters can be not only hexagonal (honeycomb-like).
"We observed shapes, atypical and "forbidden" for colloidal crystals: square, pentahedral and heptahedral. Moreover, if you add one more drop to the cluster, its whole structure will reform. It’s much more convenient to work with such small clusters in individual tasks: there are fewer drops, and it’s easier to track them," Nosonovsky explained.
Droplet water clusters were discovered in 2004 by Alexander Fedorets, Doctor of Technical Sciences, Head of the Microhydrodynamic Technologies Laboratory of the UTMN Institute of Environmental and Agricultural Biology. Currently, similar clusters are being studied in Russia, Japan, the United States, and Israel.
Today, one of the scientists’ priority tasks is to create unique technologies to study microorganisms at the level of a separate aerosol microdroplet tracked in time. The research was supported by the Russian Science Foundation.