Bubbles that last for years

The newspaper Le Monde and thejournal Nature,among others, hailed the discovery. Michaël Baudoin’s team at the Institute of Electronics, Microelectronics and Nanotechnology (IEMN¹) succeeded in making a bubble that lasted 465 days, a record for a bubble in a standard atmosphere. The secret lies mainly in two ingredients. The first are tiny plastic particles which, by forming ‘capillary bridges’ between themselves and the liquid, prevent the water contained in the walls from draining away. But that’s not enough: water bubbles just covered with particles would only last a few tens of minutes.

To make them virtually everlasting, you need to add a second ingredient, one that is well known to fans of giant bubbles: a sweet, viscous liquid called glycerol, a substance that tends to absorb moisture from the air. It is this absorption that compensates for the natural evaporation of water. Models produced by the team showed that an equilibrium was thus established, enabling the bubble to become very stable: it was probably the moulds which, by feeding on the glycerol, eventually hastened the end of the valiant bubble. Future work by the team will enable us to study the reasons for this extraordinary stability in greater detail.