Scientists have created miniature versions of Saturn, complete with rings, by electrifying tiny droplets of fluids. The advance may pave the way for generating microscopic and uniform particles and capsules which are often used in products such as drugs, inks, cosmetics and paints.
When a drop of electrically conductive liquid is exposed to an electric field, the droplet responds by forming two electrically charged poles.
Previous research has shown that these poles can get pulled towards the sources of the electric field, taking on cone shapes. If the pull is strong enough, the tips of the cones can spray jets of droplets. Experiments regarding this effect, known as electrospraying, often involved drops of liquid surrounded by less electrically conductive fluids.
Researchers from Northwestern University in the US, and colleagues wanted to explore what happens when drops of liquid are submerged in more electrically conductive fluids -specifically, drops of silicone oil suspended in castor oil.
When an electric field is applied to a drop of silicone oil suspended in castor oil, the drop can flatten and emit rings of fluid from its equator that break up into droplets.
If an electric field is strong enough, researchers found that the equators of these squashed drops emit concentric rings of droplets, making the drops look like miniature versions of Saturn.
In experiments, drops of silicone oil about one millimetre wide generated droplets that were about 100 times smaller, Petia Vlahovska from Northwestern University told ‘Live Science’. Vlahovska noted they could generate rings in a very controllable way. Future research will explore what materials can be used to produce this “ring of particles” effect.
“The broader the range of materials, the wider the applications will be,” Vlahovska said. The findings will be published in the journal Physical Review Letters.