Capillary Wicking on Heliamphora minor-Mimicking Mesoscopic Trichomes Array

Area of Science:

• Fluid dynamics
• Surface science
• Biomimetics

Background:

• Capillary wicking is liquid spreading on rough, lyophilic surfaces, crucial for microfluidics.
• Mesoscale roughness studies are limited by fabrication challenges.
• The pitcher plant (Heliamphora minor) offers a natural model for wicking on pubescent surfaces.

Purpose of the Study:

• To investigate capillary wicking in mesoscopic structures.
• To develop a biomimetic fabrication technique for studying high-flux wicking.
• To understand the dynamics and scaling laws of mesoscale capillary wicking.

Main Methods:

• 3D printing to create a mesoscopic trichome array mimicking Heliamphora minor.
• Experimental investigation of capillary wicking dynamics on the fabricated surface.
• Analysis of fluid transport within non-uniformly thick films.

Main Results:

• A non-uniform film thickness was observed due to interval filling of mesoscopic structures.
• An inertia-dominated transition regime was identified, differing from microscale viscous dissipation.
• A scaling law (height ~ time^(2/3)) was established for mesoscopic wicking.
• An open system siphon with experimentally determined flux saturation was realized.

Conclusions:

• Mesoscopic capillary wicking exhibits unique dynamics distinct from microscale phenomena.
• 3D printing enables fabrication of biomimetic structures for studying complex fluid transport.
• This research opens avenues for low-cost, high-flux open fluidic systems.