From inkjet printing to fine sprays, the motion and breakup of liquid droplets shape countless everyday processes. But how do droplets influence one another, how far can they travel, and what determines when a liquid jet breaks apart?
In the Soft Matter group, we investigate these questions using precisely controlled droplet trains, high-speed imaging, and experimental fluid dynamics. We explore how interactions between neighbouring droplets affect their motion and coalescence, and how surrounding air influences the formation and propagation of spray clouds.
Our research also reveals how tiny thermal fluctuations can trigger the breakup of liquid jets, connecting the physics of nanoscale jets to everyday dripping and spraying. Together, these studies uncover the fundamental mechanisms governing drops, jets, and sprays.
Understanding how droplet interactions, surrounding air, and microscopic fluctuations govern the formation, motion, and breakup of liquid sprays.
Selected Publications
Recent research exploring the physics of droplets, jets, and sprays.
A. Parrenin, C. van Rijn & D. Bonn · Physical Review Fluids · 2026
How does surrounding air shape a spray? Experiments reveal that friction with air drives the formation of expanding spray clouds, while reducing ambient pressure can suppress their characteristic spreading altogether.
S. Kooij, D. T. A. Jordan, C. J. M. van Rijn, N. M. Ribe & D. Bonn · Physical Review Letters · 2025
Why does a liquid jet eventually break into droplets? This study demonstrates that intrinsic thermal capillary waves can initiate jet breakup, providing a unified explanation across scales from nanojets to everyday liquid streams.
A. Parrenin, S. Kooij, C. J. M. van Rijn & D. Bonn · Physics of Fluids · 2024
Droplets travelling together behave differently from isolated drops. This work investigates how collisions and coalescence change droplet size distributions and influence the propagation of droplet trains.
S. Kooij, C. van Rijn, N. Ribe & D. Bonn · Scientific Reports · 2022
Liquid sprays can acquire electrical charge during their formation. This study explores the mechanisms behind spray self-charging, adding another dimension to our understanding of droplet generation and behaviour.
Research contact: Daniel Bonn · d.bonn@uva.nl ↗