Continuous fabrication process for double sided micro/nanopatterns

Abstract

Although roll to roll nanoimprint lithography (R2RNIL) is capable of continuously producing micro/nanopatterns over a large area at high speed, it is inherently limited by the opacity of the master mould to single sided substrate patterns. This study therefore demonstrates a double sided continuous process, wherein a transparent rigiflex mould is utilised. This is shown to allow continuous imprinting of micro- or nanopatterns over a large area (10 cm wide) by using a remodelled roll to roll imprinting apparatus, and a polyethylene terephthalate (PET) film as a flexible substrate. A maximum production speed of 3 cm s−1 was achieved with a micro prism pattern, in which 150 nm wide nanogratings and 700 nm diameter nanoposts were continuously patterned on a flexible substrate, and also a solid glass substrate. To demonstrate the feasibility of its commercial application, a multifunctional optical film was fabricated with a prism pattern on one side, and a wire grid polarising pattern on the other.