Universality of breath figures on two-dimensional surfaces: an experimental study

TL;DR

This experimental study demonstrates that droplet patterns formed by condensation, known as breath figures, follow universal scaling laws across diverse substrates, confirming the universality of their self-organized structures.

Contribution

The paper provides the first comprehensive experimental validation of the universality of breath figure scaling functions across various surface properties.

Findings

Droplet size distributions collapse onto universal scaling functions.

Surface coverage and droplet number follow universal time-asymptotic scaling.

Universality holds despite differences in substrate chemistry, stiffness, and condensation rates.

Abstract

Droplet condensation on surfaces produces patterns, called breath figures. Their evolution into self-similar structures is a classical example of self-organization. It is described by a scaling theory with scaling functions whose universality has recently been challenged by numerical work. Here, we provide a thorough experimental testing, where we inspect substrates with vastly different chemical properties, stiffness, and condensation rates. We critically survey the size distributions, and the related time-asymptotic scaling of droplet number and surface coverage. In the time-asymptotic regime they admit a data collapse: the data for all substrates and condensation rates lie on universal scaling functions.