Year: 2025
Type: article
Abstract: Wall-attached bubbles can produce repeated jets under gentle ultrasound stimulation through the Faraday instability. We identify three distinct jetting regimes defined by the jetting frequency and the bubble surface topology. We demonstrate that these jets form via flow-focusing singularities following two distinct collapse modes of the bubble interface: conical, producing a jet toward the substrate, or parabolic, generating a pair of oppositely directed jets. Scaling laws governing these collapse events are derived, revealing a universal self-similar structure governed by inertia and capillarity. Furthermore, we establish the dependence of the interface acceleration for jetting on driving frequency and characterize the jet speed as a function of Faraday wave height and bubble size. These findings may inform the design of low-power biofilm removal ultrasound systems and contribute to improved safety in targeted drug delivery.
Source: Physical Review Letters
DOI: 10.1103/7c4p-y9jr
Authors: Marco Cattaneo, Louan Presse, Outi Supponen
Institution: ETH Zurich
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4416149344