Self‐Driven Droplet Motions Below their Icing Points

Abstract

AbstractLiquid fluidity is a most key prerequisite for a broad range of technologies, from energy, fluid machineries, microfluidic devices, water, and oil transportation to bio‐deliveries. While from thermodynamics, the liquid fluidity gradually diminishes as temperature decreases until completely solidified below icing points. Here, self‐driven droplet motions are discovered and demonstrated occurring in icing environments and accelerating with both moving distances and droplet volumes. The self‐driven motions, including self‐depinning and continuous wriggling, require no surface pre‐preparation or energy input but are triggered by the overpressure spontaneously established during icing and then continuously accelerated by capillary pulling of frosts. Such self‐driven motions are generic to a broad class of liquid types, volumes, and numbers on various micro‐nanostructured surfaces and can be facilely manipulated by introducing pressure gradients spontaneously or externally. The discovery and control of self‐driven motions below icing points can greatly broaden liquid‐related applications in icing environments.