Droplet Migration on Conical Fibers

TL;DR

This study investigates how droplets spontaneously move on conical fibers, combining experiments and a simple theoretical model to predict droplet speed based on geometry and fluid properties.

Contribution

It introduces a predictive model for droplet migration on conical fibers validated by experimental data.

Findings

Droplet speed depends on fiber geometry and fluid properties.

The theoretical model accurately predicts experimental droplet speeds.

Experimental data align well with the proposed viscous-surface tension balance.

Abstract

The spontaneous migration of droplets on conical fibers is studied experimentally by depositing silicone oil droplets onto conical glass fibers. Their motion is recorded using optical microscopy and analysed to extract the relevant geometrical parameters of the system. The speed of the droplet can be predicted as a function of geometry and the fluid properties using a simple theoretical model, which balances viscous dissipation against the surface tension driving force. The experimental data are found to be in good agreement with the model.