Hybrid hierarchical patterns of gold nanoparticles and poly(ethylene glycol) microstructures

Hybrid surface micro-patterns composed of topographic structures of polyethylene glycol (PEG)-hydrogels and hierarchical lines of gold nanoparticles (Au NPs) were fabricated on silicon wafers. Micro-sized lines of Au NPs were first obtained on the surface of a silicon wafer via “micro-contact deprinting”, a method recently developed by our group. Topographic micro-patterns of PEG, of both low and high aspect ratio (AR up to 6), were then aligned on the pre-patterned surface via a procedure adapted from the soft lithographic method MIMIC (Micro-Molding in Capillaries), which is denoted as “adhesive embossing”. The result is a complex surface pattern consisting of alternating flat Au NP lines and thick PEG bars. Such patterns provide novel model surfaces for elucidating the interplay between (bio)chemical and physical cues on cell behavior.