Topography-induced symmetry transition of droplets on quasi-periodically patterned surfaces

TL;DR

This study demonstrates how quasi-periodic surface structures influence droplet morphology, leading to spontaneous symmetry restoration and complex shape control, advancing surface patterning techniques.

Contribution

It introduces the use of quasi-periodic structures for controlling droplet symmetry transitions, revealing the roles of surface topography and self-similarity.

Findings

Droplets form 5-fold symmetric shapes on quasi-periodic surfaces.

Symmetry spontaneously restores during droplet spreading.

Surface topography and self-similarity are key factors in shape determination.

Abstract

Quasi-periodic structures of quasicrystals yield novel effects in diverse systems. However, there is little investigation on employing quasi-periodic structures in the morphology control. Here, we show the use of quasi-periodic surface structures in controlling the transition of liquid droplets. Although surface structures seem random-like, we find that on these surfaces, droplets spread to well-defined 5-fold symmetric shapes and the symmetry of droplet shapes spontaneously restore during spreading, hitherto unreported in the morphology control of droplets. To obtain physical insights into these symmetry transitions, we conduct energy analysis and perform systematic experiments by varying properties of both liquid droplet and patterned surface. The results show the dominant factors in determining droplet shapes to be surface topography and the self-similarity of the surface structure. Our findings significantly advance the control capability of the droplet morphology. Such a quasi-periodic patterning strategy can offer a new method to achieve complex patterns.