Three-dimensional superhydrophobic structures printed using solid freeform fabrication tools

Abstract

Superhydrophobic surfaces are of fundamental and commercial interest as water does not wet the surface, leading to unique properties such as low slip angle, high contact angle, and icephobicity. These behaviours are achieved through a combination of low surface energy materials and high surface roughness. Two printing techniques were used to fabricate hydrophobic polymers into superhydrophobic surfaces. In one approach, a commercially available multi-jet modelling rapid prototyping machine was used to fabricate 3D superhydrophobic objects including helical conduits and porous membranes, using the standard printer resins. A robotic dispensing tool was also developed that enables greater freedom of material selection and feature shape. Both approaches were used to fabricate arrays of high aspect ratio surface features on which water assumes a nearly spherical shape and easily rolls off the surface at low tilt angles. The fabrication and wetting properties of surfaces made using these two techniques will be discussed.