Self-regulating surfaces for efficient liquid collection

TL;DR

This paper introduces a novel surface design using filmwise wetting and curvature-induced Laplace pressure gradients to regulate liquid flow, enhancing efficiency in various liquid collection applications.

Contribution

It presents a new framework for designing surfaces that control liquid flow through curvature and wetting properties, surpassing traditional non-wetting surface methods.

Findings

Curvature-induced Laplace pressure gradients enable effective liquid regulation.

Surface parameters like scale and curvature significantly influence capillary flow.

The design framework can be tailored for diverse applications like HVAC and water harvesting.

Abstract

To achieve efficient liquid collection, a surface must regulate incoming liquid accumulation with outgoing liquid transport. Often, this can be proposed to be achieved by functionalizing surfaces with non-wetting characteristics. Yet, there remain fundamental, practical limits to which non-wetting surfaces can effectively be employed. We instead utilize filmwise wetting to achieve liquid regulation via a Laplace pressure gradient induced by solid surface curvature. The key parameters affecting this capillary flow are then introduced, namely solid properties like scale and curvature and liquid properties like surface tension and density. The liquid regulation mechanism can then be employed in condensation and aerosol processes to generate enhanced flow, while the solid geometry needed to create this capillary flow itself is capable of affecting and enhancing liquid generation. Ultimately, the surface design framework can be customized to each unique application to optimize processes in HVAC, industrial steam generation, chemical depositions, and atmospheric water harvesting.