---
title: "Migrating cell clusters as active droplets with asymmetric shape and contact angles"
authors:
  - "Hanno I. Hennighausen"
  - "Jaime A. Espina"
  - "Elias H. Barriga"
  - "Ricard Alert"
year: 2026
venue: "arXiv:physics.bio-ph"
arxiv: "2610.03536"
doi: null
source: "https://arxiv.org/abs/2610.03536"
topics:
  - "curiosity"
  - "biology"
  - "biophysics"
  - "active-matter"
  - "wetting"
seed_rank: 1851
seed_batch: "curiosity-2026-10-07"
reviewed: "2026-10-07"
pool: "biology"
relevance_score: 8
lineage: tissue-mechanics
cites:
  - title: "Migrating cell clusters as active droplets with asymmetric shape and contact angles"
    url: "https://arxiv.org/abs/2610.03536"
    year: 2026
    arxiv: "2610.03536"
    doi: null
see:
  - "1089-life-at-low-reynolds-number"
  - "521-the-chemical-basis-of-morphogenesis"
---

# Migrating cell clusters as active droplets with asymmetric shape and contact angles

## One-sentence takeaway

Migrating clusters of frog neural crest cells are lopsided droplets, flatter at the front than at the rear, and an active-wetting model in which traction-driven pressure gradients bend the surface (Young–Laplace) explains the shape and lets you read off tissue viscosity.

## Why it's lovely

Why you might love this: embryos move tissue around like a blob of fluid crawling uphill on a wettability gradient. The old active-wetting picture forced the cluster into a symmetric spherical cap; here the shape is solved for, not assumed. Asymmetric tractions create a pressure gradient across the tissue, Young–Laplace turns that into a curvature gradient on the top surface, and fitting the measured height profile gives the tissue's viscosity. Soft-matter physics doing developmental biology, from the same continuum family as Turing (521) and Purcell's low-Reynolds world (1089); a nice reference model for blob-like units or gooey creatures in a sim.

## Key ideas

- Experiment: migrating frog neural crest clusters show asymmetric height profiles, lower contact angle at the front than the rear.
- Extend the active-wetting model with an equation for the cluster shape, which becomes part of the solution.
- Asymmetric tractions drive migration and generate a tissue pressure gradient.
- Young–Laplace converts the pressure gradient into a curvature gradient on the upper surface, giving front/rear contact-angle asymmetry.
- Fitting theory to the measured profile estimates tissue viscosity; general mechanism for asymmetric shapes of migrating clusters as active droplets on a wettability gradient.

## Caveats

Continuum, thin-film-style model of a specific system (neural crest explants); individual-cell mechanics are coarse-grained away. Viscosity is an inferred fit parameter. Recent preprint.

## Links

- arXiv abs: https://arxiv.org/abs/2610.03536
- PDF: https://arxiv.org/pdf/2610.03536