  In this manuscript we introduce cubic bubbles that are pinned to 3D printed
millimetric frames immersed in water. Cubic bubbles are more stable over time
and space than standard spherical bubbles, while still allowing large
oscillations of their faces. We found that each face can be described as a
harmonic oscillator coupled to the other ones. These resonators are coupled by
the gas inside the cube but also by acoustic interactions in the liquid. We
provide an analytical model and 3D numerical simulations predicting the
resonance with a very good agreement. Acoustically, cubic bubbles prove to be
good monopole sub-wavelength emitters, with non-emissive secondary surfaces
modes.
