Large-area Sub-micron Structured Surfaces Using Micro Injection Moulding Templates of Nanoporous Anodized Aluminum Oxide

This study demonstrates a mass production method using nanoporous Anodized Aluminum Oxide (AAO) templates as mould insert tools that are used to structure large area polymer surfaces by a micro injection moulding process. SEM and water contact angle measurements served to evaluate the effect of nanostructures on surface properties. Human umbilical vein endothelial cells were cultured on nano-structured and ultra-smooth surfaces of polymer parts. Experimental results indicated that nano-pillar features sized from ~100nm to 250nm were easily replicated on these same polymer surfaces. The contact angles varied from 3 to 9. The nanoporous AAO templates were able to retain their pore integrity very well for ~80 injection moulding cycles: this suggests they they could be a potential mould tool for large area patterning of polymer surfaces. The endothelial cell culture analysis indicates that cell growth was not significantly affected by nano-topography compared to the smooth surfaces (baseline RA ~6nm) and both surfaces had equally good cell adhesion.