Droplet on a sugar fiber

TL;DR

This study investigates the behavior of water droplets on vertical sugar fibers, analyzing conditions for suspension, movement, and detachment, and presents a phase diagram and model for critical droplet volume based on fiber diameter.

Contribution

It introduces a phase diagram and a model to predict droplet behavior on sugar fibers, highlighting the conditions for upward movement and detachment.

Findings

Droplets can remain suspended or move along the fiber depending on volume.

A phase diagram maps droplet behavior based on volume and fiber diameter.

A model predicts the critical droplet volume for detachment.

Abstract

The motion of a water droplet on a single vertical sugar fiber is analyzed. The fiber is positioned vertically, with the droplet placed at its pending end. If the capillary force exceeds the weight of the droplet, the droplet remains suspended at the fiber's extremity. As water dissolves, the fiber eventually breaks. Subsequently, the droplet may fall down carrying a portion of the undissolved fiber or, more interestingly, the droplet may be propelled upwards, remaining attached to the fiber. The process can then restart. A phase diagram is constructed based on the droplet's volume and the fiber's diameter. A model has been built to assess the critical droplet volume for a given fiber diameter, above which the droplet falls. Below this volume, the droplet can move upwards along the fiber.