Vapor-Induced Liquid Collection and Microfluidics on Superlyophilic Substrates

Liquid manipulation on solid surfaces has attracted a lot of attention for liquid collection and droplet-based microfluidics. However, manipulation strategies mainly depend on chemical modification and artificial structures. Here, we demonstrate a feasible and general strategy based on the self-shrinkage of the droplet induced via specific vapors to efficiently collect liquids and flexibly carry out droplet-based reactions. The vapor-induced self-shrinkage is driven by Marangoni flow originating from molecular adsorption and diffusion. Under a specific vapor environment, the self-shrinking droplet exhibits unique features including reversible responsiveness, high mobility, and autocoalescence. Accordingly, by building a specific vapor environment, the thin liquid films and random liquid films on superlyophilic substrates can be recovered with a collection rate of more than 95%. Moreover, the vapor system can be used to construct a high-efficiency chemical reaction device. The findings and profound understandings are significant for the development of the liquid collection and droplet-based microfluidics.

Automated summary

This study demonstrates a new method of self-shrinkage of droplets induced by specific vapors for efficient liquid collection and flexible droplet reactions. The research findings show that under specific vapor environments, self-shrinking droplets exhibit reversible responsiveness, high mobility, and autocoalescence, which can be used for liquid collection on superlyophilic substrates.