Self-assembly of highly ordered micro- and nanoparticle deposits

Hossein Zargartalebi; S Hossein Hejazi; Amir Sanati-Nezhad

doi:10.1038/s41467-022-30660-6

Self-assembly of highly ordered micro- and nanoparticle deposits

Nat Commun. 2022 Jun 2;13(1):3085. doi: 10.1038/s41467-022-30660-6.

Authors

Hossein Zargartalebi^{1

2}, S Hossein Hejazi³, Amir Sanati-Nezhad^{4

5}

Affiliations

¹ Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
² BioMEMS and Bioinspired Microfluidic Laboratory, Department of Biomedical Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
³ Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
⁴ Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada. amir.sanatinezhad@ucalgary.ca.
⁵ BioMEMS and Bioinspired Microfluidic Laboratory, Department of Biomedical Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada. amir.sanatinezhad@ucalgary.ca.

Abstract

The evaporation of particle-laden sessile droplets is associated with capillary-driven outward flow and leaves nonuniform coffee-ring-like particle patterns due to far-from-equilibrium effects. Traditionally, the surface energies of the drop and solid phases are tuned, or external forces are applied to suppress the coffee-ring; however, achieving a uniform and repeatable particle deposition is extremely challenging. Here, we report a simple, scalable, and noninvasive technique that yields uniform and exceptionally ordered particle deposits on a microscale surface area by placing the droplet on a near neutral-wet shadow mold attached to a hydrophilic substrate. The simplicity of the method, no external forces, and no tuning materials' physiochemical properties make the present generic approach an excellent candidate for a wide range of sensitive applications. We demonstrate the utility of this method for fabricating ordered mono- and multilayer patternable coatings, producing nanofilters with controlled pore size, and creating reproducible functionalized nanosensors.