Physicists "spill" a bubble

When you burst a bubble, it quickly disintegrates into liquid droplets before your eyes and disappears almost instantly. Although this process may seem relatively unimportant, scientists have long been interested in the underlying physics and chemistry, as bubble formation plays a key role in a wide range of industries.

A team of researchers, led by Duyang Zang of Northwestern Polytechnic University in China, has managed to reverse the phenomenon of turning liquid droplets into bubbles.

To do this, they used a technique called "acoustic levitation", commonly used to study the dynamics of liquid droplets. It allows scientists to levitate droplets in the air by using sound waves and manipulating their shape by adjusting the sound intensity or the sound field distribution.

Previously, researchers used acoustic levitation to deform liquid droplets by flattening them into a thin film or inducing buckling in their shape.

In an article published in the journal Nature Communications, the researchers described how they combined these two approaches to achieve controlled bubble formation.

First, they levitated a liquid droplet and distorted it into a thin film using sound waves. They then adjusted the sound field to curl the flattened droplet into a bowl shape, manipulating it further until it became a sphere with an air cavity inside. – in other words, a bubble. You can see this process at work in the video above.

"Similar phenomena have been observed before, but this is the first time that the underlying mechanism has been discovered," said Duyang Zang, senior author of the Northwestern Department of Applied Physics study. Newsweek.

See all best photos of the week in these slideshows

"In addition, this is the first time that the bubble can be formed in a controlled manner via this mechanism," he added. "We can adjust the volume of the air cavity by pulling from the outside to trigger the transition."

Stock image of a bubble. iStock

According to the researchers, the latest discoveries could have implications in many areas, as bubble formation is a critical process in the preparation of foams, which are widely used in the food, cosmetic, pharmaceutical and food industries. ultra-light materials. among others.

According to Zang, some possible applications of this technique could be to encapsulate drugs in the form of tiny bubbles to administer drugs or to use levitated bubbles as templates for assembling nanomaterials.