Abstract
Collecting energy from the time-dependent electrodynamic fields into a vacuum volume can be substantially assisted by spherical metasurfaces wrapped around the respective domains. The combinations of sizes and surface admittances that lead to maximal concentration of power into the cells are identified and enhancement by several orders of magnitude has been recorded. The spatial distribution of the signals in the vicinity of these meta-bubbles unveils the nature of the sustained resonances and demonstrates their ability to wirelessly couple with other equipment nearby. The reported optimal regimes of operation can be employed in integrated photonic systems involving an extensive range of applications from energy storage and optical memory to electromagnetic filtering and power accumulation.