Elastocapillarity-assisted spontaneous particle clustering system: Parallel observation of enhanced interparticle reaction utilizing evaporative preconcentration

Abstract

Elastocapillarity is a spontaneous phenomenon wherein a solid structure is deformed by capillary forces generated by liquid evaporation between solid structures. In general, elastocapillarity has been considered as a bottleneck that causes stiction, which irreversibly damages microstructures during the wet process in microelectromechanical system fabrication. In this study, elastocapillarity, as an autonomous driving force, is utilized in an open-microfluidic environment for enabling self-driven particle docking without any external equipment in a user-friendly manner. Accordingly, elastocapillarity on flexible microplates, which can be reversibly deformed and restored, is utilized as a key concept of a switchable elastocapillary functional (SELF) valve. The SELF valve affords particle securing, pairing, and clustering in the preferred order, while achieving a clustering efficiency of ∼95%. In addition, as all procedures are conducted in an open-microfluidic environment, the spontaneous evaporative preconcentration of samples is exploited for the effective enrichment on receptor-coated particles in traps. Finally, a cross-contamination-free multiplex analysis of the shape/color-encoded particle cluster is performed. Based on an effective combination of several techniques, including particle clustering, evaporative preconcentration, and immiscible oil partitioning for preservation/isolation of water plugs, the device was highlighted as an alternative to state-of-art techniques widely applied in the suspension-mediated multiplex analysis.