Uni‐Directional Transportation on Peristome‐Mimetic Surfaces for Completely Wetting Liquids

Abstract

AbstractLiquid uni‐directional transport on solid surface without energy input would advance a variety of applications, such as in bio‐fluidic devices, self‐lubrication, and high‐resolution printing. Inspired by the liquid uni‐directional transportation on the peristome surface of Nepenthes alata, here, we fabricated a peristome‐mimicking surface through high‐resolution stereo‐lithography and demonstrated the detailed uni‐directional transportation mechanism from a micro‐scaled view visualized through X‐ray microscopy. Significantly, an overflow‐controlled liquid uni‐directional transportation mechanism is proposed and demonstrated. Unlike the canonical predictions for completely wetting liquids spreading symmetrically on a high‐energy surface, liquids with varied surface tensions and viscosities can spontaneously propagate in a single preferred direction and pin in all others. The fundamental understanding gained from this robust system enabled us to tailor advanced micro‐computerized tomography scanning and stereo‐lithography fabrication to mimic natural creatures and construct a wide variety of fluidic machines out of traditional materials.