Agrež and colleagues vibrate the cathode of an alkaline electrolyser at around 100 kHz and watch with high-speed imaging what happens to the hydrogen bubbles clinging to it. The bubbles detach and migrate across the surface into spatial patterns that follow the electrode's vibrational modes and look like Chladni figures. Pressure-field measurements and the Keller-Miksis model support the primary Bjerknes force — bubbles driven along acoustic pressure gradients towards the nodes — as the mechanism.
The payoff is electrical: overvoltage dropped by 20 per cent within 100 milliseconds of switching the vibration on during a two-second burst, and took seven seconds to recover afterwards, which suggests pulsed rather than continuous driving is the efficient strategy.
For a studio that spends its time on bubbles, this is a useful reminder that a bubble in a sound field is not a passive marker. It is an oscillator with its own response, and it goes where the pressure field tells it.