New preprint 🥳
In our new paper, we show that “Advection selects pattern in multi-stable emulsions of active droplets” — which provides a path toward controlling regular arrangements of droplets. 🧵
📄 arxiv.org/abs/2510.00827

Chemically Active Liquid Bridges Generate Repulsive Forces Droplets help organize cells by compartmentalizing biomolecules and by mediating mechanical interactions. When bridging two structures, such droplets generate capillary forces, which depend on surface...

Many thanks to Frieder Johannsen and the @zwicker-group!
📄 arxiv.org/abs/2509.18777

🔬 Cells use droplets to organize their interior, sometimes forming liquid bridges between intracellular structures.
While passive bridges attract, we show that activity can make them repel. Cells might use this to control organelle placement & morphology.

By combining the fixed bridge radius with a thin-interface approximation, we derived an analytic force expression for a cylindrical active bridge.

✅ It matches the scaling found in simulations—showing that size control is the main driver of the observed effects.

Why?
Passive: Stretching increases surface energy, pulling walls together
Active: Chemical reactions maintain fixed bridge radius regardless of wall separation
👉 The bridge doesn't thin but can grow in volume → it is energetically favorable for the walls to move apart, generating repulsion.

New preprint 🎉
What began as Frieder Johannsen’s bachelor thesis in the @zwickergroup.bsky.social (which I had the pleasure to supervise) evolved into our latest paper: “Chemically Active Liquid Bridges Generate Repulsive Forces” — unlike passive ones, which attract.
📄 arxiv.org/abs/2509.18777