Multifunctional Hairy Textures Fabricated with Embedded 3D Printing

Long slender hairs grow and surface and form very soft textures due to their slenderness. We developed a new embedded 3D printing method to print hairs with a high aspect ratio and controlled spacing. Embedded 3D printing is a direct ink writing technique conducted inside a support gel, not in the air. The gel allows the printed fibers to rapidly solidify and stiffen by the solvent exchange method, while remaining supported by the gel to resist gravitational forces during the printing process. With the method, we were able to fabricate hairy surfaces where the fibers are rooted in a PDMS substrate. First, the printability window and parameters will be presented. Then, the multifunctionality of the surface textures will be demonstrated via the elastocapillary effect and the hair bending mechanism will be explained with scaling laws.