Fabrication and surface functionalization of high aspect ratio plastic nanostructures

Soft UV nanoimprint lithography and reactive ion etch techniques have been used to pattern high density and high aspect ratio nanostructures on the surface of a plastic plate such as Plexiglas. A thin film of photo-curable resist is first spin coated on the plastic plate, with or without deposition of a 10 nm thick germanium intermediate layer. Then, a soft stamp made of poly-dimethylsiloxane (PDMS) is used to mold the photo-curable resist, followed by a UV light exposure. Finally, the imprinted pattern is used as mask for a sequential reactive ion etch of the residual resist layer, the intermediate layer if any, and the plastic plate. Such a soft nanoimprint and direct etch technique allowed us to obtain high density nanostructures with an aspect ratio up to 15. To demonstrate the applicability of such systems in biology, wetting behaviours and surface functionalization with fluorescent protein molecules have been studied. We believe that this low cost approach is high throughput and efficient for a number of applications.