Fabricating three-dimensional periodic micro patterns on photo-resists using laser interference lithography

Springtails are hexapods, which have a complex skin surface composed of periodically arranged mushroom-like features. This topography offers surface functionalities like non-wetting and preventing bacterial settlement. This study demonstrates a novel way of replicating the morphology of the springtail skin using interference lithography. The micro patterns are produced with an undercut contour in a multilayer resist system on Si-wafers consisting of a lower lift-off resist and an upper photo-sensitive resist. After irradiation, several developing and rinsing steps are carried out to produce cavities in the lift-off resist layer with an undercut geometry directly below the SU-8 top layer.