  In this paper, we study the dynamics of cylindrical armoured bubbles excited
by mechanical vibrations. A step by step transition from cylindrical to
spherical shape is reported as the intensity of the vibration is increased,
leading to a reduction of the bubble surface and a dissemination of the excess
particles. We demonstrate through energy balance that nonspherical armoured
bubbles constitute a metastable state. The vibration instills the activation
energy necessary for the bubble to return to its least energetic stable state:
a spherical armoured bubble. At this point, particle desorption can only be
achieved through higher amplitude of excitation required to overcome capillary
retention forces. Nonspherical armoured bubbles open perspectives for tailored
localized particle dissemination with limited excitation power.
