Surfactant onions form when layers of surfactant molecules organize around each other into a sphere. They are easily pictured by thinking of their vegetable namesake. Until now it has not been clear whether surfactant onions are perfect layered structures or whether they contain defects. Researchers from the University of Tokyo Institute of Industrial Science have used microscopy to get a better understanding of surfactant onion layers, which is important for their potential application. Their findings are published in Physical Review Research.
source https://phys.org/news/2021-11-optical-microscopy-beneath-skin-surfactant.html