Injection molded superhydrophobic surfaces

E. Søgaard, K. Smistrup, R. Taboryski
Technical University of Denmark, DK

Keywords: injection molding, black silicon, superhydrophobic, polymer, surface functionalization

Summary:

The Lotus effect is used as inspiration for the fabrication of injection molded (IM) hierarchical polymer surfaces with self-cleaning properties. IM is a widespread method for the fabrication of plastic items. Surface functionalization is traditionally done by potentially toxic and expensive chemical coatings. Here we present a new method for the fabrication of tool inserts with hierarchical nano- and microstructures. The method is based on a UV LIGA process combined with a black silicon (BS) etch. . The advantage of our method is the industrial manufacturability associated with IM. Preliminary results indicate a contact angle increase from 95° for the unstructured polymer to a maximum 150°.The lowest drop roll off angels observed were in the range 1° to 5°. It was nearly impossible to deposit a drop on the surface.