Professor Zang Duyang's team from College of Physical Science and Technology, Northwestern Polytechnical University headquartered in Xi’an, Shaanxi province in Northwest China, recently set a Guinness World Record by creating the "longest lifespan bubble on the ground".

Under acoustic levitation conditions, the bubble retention time can reach 23 minutes and 36 seconds, and the suspended bubble can still remain unbroken when penetrated by a hot copper needle with a diameter of 0.8 millimeters.

Guinness World Record Certificate awarded to Professor Zang Duyang's team.

Professor Zang Duyang (middle) and his team of students.

Bubbles play a familiar and indispensable role in people's production and life. Due to their unique interface physical and chemical properties and dynamic behavior, especially the unique heat and mass transfer boundary conditions and two-dimensional flexible confinement provided by bubble membranes for many specific physical and chemical processes, bubbles have broad application prospects in fields such as material engineering, fluid physics, life sciences, and environmental sciences.

However, due to gravity induced drainage and the large specific surface area of the bubbles themselves, they are inherently unstable.

The common bubbles in nature often only exist for a few seconds and burst upon contact, which greatly limits their wide application and important role in production and life due to their short lifespan and poor stability.

Therefore, extending the lifespan of bubbles has become an interesting challenge for many scholars and engineers in fields such as fluid physics and soft matter.

“Our research group has been conducting research on soft matter and complex fluids, with a particular focus on the physical, mechanical, and chemical coupling issues at the interface of soft matter, "said professor Zang Duyang.

In an experiment, the research group accidentally discovered that droplets can be transformed into bubbles under acoustic suspension conditions, and the survival time of acoustic suspension bubbles is significantly better than that of conventional bubbles, even when punctured with a needle, they can still remain intact.

This outstanding feature has delighted the research team and aroused great scientific interest among everyone.

Why are bubbles in the sound field so 'strong' and long-lasting? Professor Zang Duyang had such a question in his mind, and begun to organize a research team to explore and summarize this issue in depth, ultimately revealing that the super stability of acoustic suspended bubbles is due to the significant suppression of gravity drainage caused by the acoustic radiation force on the inner and outer surfaces of the bubbles.

The survival time of acoustic suspended bubbles is significantly better than that of conventional bubbles, and they can even remain intact when punctured with a needle.

The research findings were published in the internationally renowned academic journal Droplet with the title "Extraordinary stability of contingent free bubbles suspended in ultrasound" as the cover story, and were highlighted in Nature.

This achievement pioneered a new method of stabilizing bubbles through ultrasonic suspension, and further revealed the physical mechanism that causes this super stability, achieving the effect of keeping bubbles stable for a long time under conventional gravity conditions, comparable to the suppression of liquid discharge in microgravity environments in space stations, and providing a ground simulation approach suitable for the study of bubbles and bubble membranes in space environments.

Guided by this achievement, Professor Zang Duyang's research group created the "longest lifespan bubble on the ground" and set a Guinness World Record: under acoustic levitation conditions, the bubble held for 23 minutes and 36 seconds.

Zang introduced that this type of acoustic suspended bubble with no solid surface contact, no chemical pollution, and ultra stability has broad application prospects in scientific research and industrial production.

For example, Zang said, the ultra-stable bubbles help measure the surface tension and rheological properties of liquids, can be used as liquid based materials for collecting and analyzing aerosol particles, can serve as ideal biological/chemical reactors, liquid templates for crystal growth, cell culture and unique microenvironment.

In the future, Professor Zang Duyang's research group will continue to conduct related research on acoustic suspended bubbles, explore the surface characteristics, dynamics, and thermodynamic properties of bubbles, and continue to promote reverse scientific research in related fields, providing theoretical support for the practical application of acoustic suspended bubbles in materials engineering, fluid physics, life sciences, and other fields.