Patterns formed by droplet evaporation from a restricted geometry

Abstract

We show that hundreds of concentric rings, each approximately nanometers high and micrometers wide, form when a drop is allowed to evaporate from a confined geometry, leaving behind a dry, nonvolatile polymer solute. This new preparative strategy offers a simple, versatile, generalizable method to produce patterns of unprecedented high fidelity and regularity, as well as a direction to look to design yet more complex patterns.