# Liquid droplets act as "compass needles" for the stresses in a deformable membrane

## TL;DR

This study shows that droplets on deformable membranes can serve as precise probes to map the stress field by analyzing their shape and contact line profile, with theoretical predictions matching experimental data.

## Contribution

The paper introduces a method to determine membrane tension and stress orientation using droplet shape analysis on anisotropic elastic films.

## Key findings

- Droplet shape elongates along high tension directions.
- Contact line profile reveals membrane tension.
- Theoretical predictions align with experimental observations.

## Abstract

We examine the shape of droplets atop deformable thin elastomeric films prepared with an anisotropic tension. As the droplets generate a deformation in the taut film through capillary forces, they assume a shape that is elongated along the high tension direction. By measuring the contact line profile, the tension in the membrane can be completely determined. Minimal theoretical arguments lead to predictions for the droplet shape and membrane deformation that are in excellent agreement with the data. On the whole, the results demonstrate that droplets can be used as probes to map out the stress field in a membrane.