Metal pumps liquid uphill

Abstract

The behavior of liquids on a solid surface is determined by the surface wettability. In this work, by structuring metal surfaces with high-intensity femtosecond laser pulses, we engineer a unique surface pattern that dramatically modifies surface wetting properties. In a gravity-defying way, the treated metal surfaces make liquids sprint vertically uphill at an unprecedented speed of 1 cm/s. Furthermore, the surface structures we create here rapidly transport a significant amount of liquid against gravitation to an elevated point above the reservoir level, thus bringing this effect to potential real-life applications.