  Small bubbles in fluids raise to the surface due to Archimede's force.
Remarkably, in turbulent flows this process is severely hindered by the
presence of vortex filaments, which act as moving potential wells, dynamically
trapping light particles and bubbles. Quantifying the statistical weights and
roles of vortex filaments in turbulence is, however, still an outstanding
experimental and computational challenge due to their small scale, fast chaotic
motion, and transient nature. Here we show that, under the influence of a
modulated oscillatory forcing, the collective bubble behaviour switches from a
dynamically localized (insulator) to a delocalized (conductor) state.
Additionally, we find that by varying the forcing frequency and amplitude, a
remarkable resonant phenomenon between light particles and small-scale vortex
filamenents emerges, likening particle behavior to a forced damped oscillator.
We discuss how these externally actuated bubbles can be used as a new type of
microscopic probes to investigate the space-time statistical properties of the
smallest turbulence scales, allowing to quantitatively measure physical
characteristics of vortex filaments. We develop a superposition model that is
in excellent agreement with the simulation data of the particle dynamics which
reveals the fraction of localized/delocalized particles as well as
characteristics of the potential landscape induced by vortices in turbulence.
Our approach paves the way to innovative ways to accurately measure turbulent
properties and to the possibility to control light particles and bubble motions
in turbulence with potential applications to wave breaking, medical imaging,
drug/gene delivery, chemical reactions, wastewater treatment, and industrial
mixing.
