New microgravity experiment: the first-ever weightless anti-bubble

New microgravity experiment: the first-ever weightless anti-bubble
From April 15 to 19, Benoit Scheid and his team produced and observed, for the very first time in the world, antibubbles in zero gravity. Their work could lead to advances in water treatment and drug encapsulation.

Twice a year, the European Space Agency (ESA) organizes weightlessness (or microgravity) flights. These flights are almost exclusively dedicated to research, and bring on board scientists from all over Europe to carry out experiments in microgravity.

Last week, an A310 took off from Bordeaux, carrying a large number of European researchers. They were accompanied by ESA astronaut candidates who were having their first experience of microgravity, with Thomas Pesquet at the controls. Of the seven experiments tested during these few days of parabolic flight, ULB was well represented, with three scientific projects, including that of Benoit Scheid’s team - Laboratoire de Transferts, Interfaces et Procédés (TIPs Lab) with colleagues from the University of Liège. The researchers’ objective was to generate and observe thermal antibubbles in weightlessness for the very first time in the world.

An antibubble is a drop enveloped by a thin membrane of gas in a liquid, giving it both the properties of a bubble in terms of gas-liquid exchange surface and those of a drop in terms of incompressibility.

The thermal antibubble in microgravity is a unique object of study, enabling us to gain a better understanding of the phenomenon of pure evaporation, limited only by heat transfer, and thus to better understand the stability mechanisms of antibubbles, without the potential interference of gravity. While some had doubts about the feasibility of the experiment in weightlessness, all went very well. " ESA is very enthusiastic about the project, and we’ve been rescheduled for the next campaign in November," says Benoit Scheid.

Practical uses for antibubbles are still in their infancy. " It’s a fundamental piece of research. I’ve been working on it for over 15 years, and we’re only now seeing the beginnings of possible applications," explains the researcher. The unique properties of antibubbles promise potential breakthroughs in water treatment, ultrasound imaging and drug encapsulation. A major challenge remains controlling the stability of these objects, which is at the heart of the study of thermal antibubbles in microgravity.

This experiment is part of the FNRS STABAB research project in which Benoit Scheid is taking part, in partnership with Stéphane Dorbolo’s team at ULiège, and follows on from their paper published at the end of 2023 in Physical Review Letters.­us/recherc­he/nouvell­e-experien­ce-en-micr­ogravite-l­a-toute-pr­emiere-ant­ibulle-en-­apesanteur