Peristome-mimetic surfaces using three-dimensional microcavities for unidirectional liquid transport

Abstract

This study presents a novel method that employs three-dimensional (3D) printing technology for fabricating a unidirectional liquid transport surface (ULTS) that mimics the peristome structure of Nepenthes pitcher plants. The molds for casting the ULTS were printed at inclined angles (15°, 20°, 25°, and 30°) to induce the staircase effect in the fused filament fabrication-type 3D printer, and the ULTS was manufactured through polymer casting. Subsequently, ULTS structures with different printing angles were analyzed, and the liquid injected onto the surface was transported in a single direction through the microcavities of the ULTS. To explain the liquid transport characteristics of the ULTS, capillary rise and Gibbs inequality were utilized. The ULTS obtained from the mold inclined at 20° (PA20) exhibited the highest transportation efficiency of 96.6%. PA20 exhibited stable unidirectional liquid transport, even in two-dimensional curved channels and arch-shaped curved surfaces. In addition, through the hydrophilic treatment of the ULTS, the water collection capacity was confirmed through a water collection test conducted on the 3D curved surface.