3D printing of soft materials with superhydrophobicity and programmable anisotropic wettability

Abstract

High water repellency and controllable wetting behavior are critical for soft devices which are prevailing in fields such as wearable electronics, healthcare and human-interactive robotics, for ensuring reliable performance and long-term use in practical environments. Although various techniques have been reported to alter surface wettability, not many of them are fit for the soft materials. In this work, superhydrophobic materials with mechanical compliance were facilely prepared by a material extrusion-based 3D printing method. The surface structures and the wetting behavior were well regulated by the designed printing path. The ultra hydrophobic performance, as well as the wetting anisotropy, was revealed and could be enhanced by deformation. Intriguingly, the wetting anisotropy can be easily tuned by varying the stretching direction and strain. Liquid transportation, microdroplet manipulation and soft gripper usage were well conducted by these 3D-printed soft surfaces, showing their appealing merits and great potentials in practical applications.