Evaporative Lithography in Open Microfluidic Channel Networks

Saifullah Lone, Jiaming Zhang, Ivan Uriev Vakarelski, Erqiang Li, Sigurdur T Thoroddsen

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

We demonstrate a direct capillary-driven method based on wetting and evaporation of various suspensions to fabricate regular two-dimensional wires in an open microfluidic channel through continuous deposition of micro- or nanoparticles under evaporative lithography, akin to the coffee-ring effect. The suspension is gently placed in a loading reservoir connected to the main open microchannel groove on a PDMS substrate. Hydrophilic conditions ensure rapid spreading of the suspension from the loading reservoir to fill the entire channel length. Evaporation during the spreading and after the channel is full increases the particle concentration toward the end of the channel. This evaporation-induced convective transport brings particles from the loading reservoir toward the channel end where this flow deposits a continuous multilayered particle structure. The particle deposition front propagates backward over the entire channel length. The final dry deposit of the particles is thereby much thicker than the initial volume fraction of the suspension. The deposition depth is characterized using a 3D imaging profiler, whereas the deposition topography is revealed using a scanning electron microscope. The patterning technology described here is robust and passive and hence operates without an external field. This work may well become a launching pad to construct low-cost and large-scale thin optoelectronic films with variable thicknesses and interspacing distances.
Original languageEnglish (US)
Pages (from-to)2861-2871
Number of pages11
JournalLangmuir
Volume33
Issue number11
DOIs
StatePublished - Mar 13 2017

Fingerprint

Dive into the research topics of 'Evaporative Lithography in Open Microfluidic Channel Networks'. Together they form a unique fingerprint.

Cite this