title: Light-Directed Particle Patterning by Evaporative Optical Marangoni Assembly.
abstract: Controlled particle deposition on surfaces is crucial for both exploiting collective properties of particles and their integration into devices. Most available methods depend on intrinsic properties of either the substrate or the particles to be deposited making them difficult to apply to complex, naturally occurring or industrial formulations. Here we describe a new strategy to pattern particles from an evaporating drop, regardless of inherent particle characteristics and suspension composition. We use light to generate Marangoni surface stresses resulting in flow patterns that accumulate particles at predefined positions. Using projected images, we generate a broad variety of complex patterns, including multiple spots, lines and letters. Strikingly, this method, which we call evaporative optical Marangoni assembly (eOMA), allows us to pattern particles regardless of their size or surface properties, in model suspensions as well as in complex, real-world formulations such as commercial coffee.
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure-PSL Research University , 24 rue Lhomond, F-75005, Paris, France.|UPMC Univ Paris 06, PASTEUR, Sorbonne Universités , F-75005, Paris, France.|UMR 8640 PASTEUR, CNRS , F-75005, Paris, France.
authors.forename: Subramanyan Namboodiri
authors.initials: SN
authors.lastname: Varanakkottu
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure-PSL Research University , 24 rue Lhomond, F-75005, Paris, France.|UPMC Univ Paris 06, PASTEUR, Sorbonne Universités , F-75005, Paris, France.|UMR 8640 PASTEUR, CNRS , F-75005, Paris, France.
authors.forename: Manos
authors.initials: M
authors.lastname: Anyfantakis
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure-PSL Research University , 24 rue Lhomond, F-75005, Paris, France.|UPMC Univ Paris 06, PASTEUR, Sorbonne Universités , F-75005, Paris, France.|UMR 8640 PASTEUR, CNRS , F-75005, Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Morel
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure-PSL Research University , 24 rue Lhomond, F-75005, Paris, France.|UPMC Univ Paris 06, PASTEUR, Sorbonne Universités , F-75005, Paris, France.|UMR 8640 PASTEUR, CNRS , F-75005, Paris, France.
authors.forename: Sergii
authors.initials: S
authors.lastname: Rudiuk
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure-PSL Research University , 24 rue Lhomond, F-75005, Paris, France.|UPMC Univ Paris 06, PASTEUR, Sorbonne Universités , F-75005, Paris, France.|UMR 8640 PASTEUR, CNRS , F-75005, Paris, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Baigl
keywords: Marangoni flow; Particle patterning; directed assembly; evaporation; photocontrol