Curvature Adjustable Liquid Transport on Anisotropic Microstructured Elastic Film

Directional liquid transport is expected via adjusting chemical components, surface morphology, and external stimuli and is critical for practical applications. Although many studies have been conducted, there are still challenges to achieving real-time transformation of liquid transport direction on the material surface. Herein, we demonstrate a strategy to achieve curvature responsive anisotropic wetting on the elastic film with V-shaped prism microarray (VPM) microstructure, which can be used to control the direction of liquid transport. The results reveal that the curvature change of an elastic film can adjust the arrangement of V-shaped prisms on the elastic film. Correspondingly, the liquid wetting trend will change and even the moving direction reverses with varying arrangements of the V-shaped prisms on the elastic film. Meanwhile, surface hydrophobicity of the VPM elastic film also affects the liquid wetting trend and even shows the opposite transport direction of the liquid, which is up to the water wetting state on the VPM elastic film. Based on these results, the VPM elastic film can serve as a valve to control the liquid transport direction and is promising in the application of liquid directional harvest, chemical reaction, microfluidic, etc.

Automated summary

Directional liquid transport is crucial for practical applications, and various methods have been explored. However, achieving real-time transformation of liquid transport direction on material surfaces remains challenging. In this study, we demonstrate a curvature responsive anisotropic wetting strategy based on V-shaped prism microarray (VPM) microstructure on an elastic film. The arrangement of V-shaped prisms on the elastic film changes with the curvature, leading to a change in liquid wetting trend and even reversal of the liquid moving direction. Additionally, the surface hydrophobicity of the VPM elastic film also affects the liquid wetting trend and can result in the opposite transport direction of the liquid.