Morphological Control of Linear Particle Deposits from the Drying of Inkjet-Printed Rivulets

TL;DR

This study investigates how the morphology of linear particle deposits from inkjet-printed rivulets can be controlled by adjusting evaporation conditions and drop overlap, revealing predictable line widths and structures.

Contribution

It demonstrates a method to control the formation of stable rivulets and their resulting particle deposit patterns through inkjet printing parameters and solvent composition.

Findings

Stable rivulets form from overlapping drops leading to three parallel lines.

Line widths depend predictably on drop spacing and size.

Drying induces monolayer particle self-assembly in specific deposit regions.

Abstract

We studied the morphology of linear particle deposits obtained by inkjet-printing of silica nanoparticle suspension in drying condition where contact line depinning occurs. We show that this evaporation mode can be obtained by adjusting the particle concentration in different solvents. For isolated drops, deposited manually or by inkjet printing, drying induces the formation of two concentric rings in which particles self-assemble into a monolayer. For fused drops, our main result is that stable rivulets could be formed by drop overlap leading, after drying, to the formation of three parallel lines composed of a self-assembled particle monolayer. The three lines are of homogeneous thickness with two very thin outer lines (~ 1 $\mu$m width) and a wider central line (~ 20 $\mu$m width). We reveal how the width of the resulting lines is influenced by drop spacing in a predictable manner for a large experimental window knowing the drop size.