Invincibubbles: Encapsulated Air in Colloidal Shells Remain Stable for Over 10 Years

More than a decade ago, we generated “invincibubbles”—air bubbles encapsulated

within silica colloidal shells—using glass capillary double emulsion microfluidic devices.

These invincibubbles remain stable and fully gas-tight to this day, representing a novel

class of durable microbubbles that withstand ultrahigh vacuum, cryogenic tempera-

tures, and extreme high temperatures. Their stability far exceeds that of conventional

bubbles with liquid interfaces and even those with particle interfaces. To demonstrate

their impermeability, we assemble a two-dimensional array of invincibubbles on a silicon

substrate, subject them to ultrahigh vacuum conditions, and deposit a thin, connected

film of superconducting materials onto their exposed surfaces. The invincibubbles retain

their structural integrity, allowing us to perform low-temperature electrical transport

measurements across their superconducting, spherical surfaces. We also quantify their

mechanical strength by measuring the tensile force of individual invincibubbles- high-

lighting a rare combination of impermeability and mechanical robustness in a colloidal-

shelled bubble system