UV-NIL replication of microlens arrays on flexible fluoropolymer substrates

This paper describes application of UV-NIL technique for the fabrication of hexagonal OrmoComp microlens arrays on flexible fluoropolymer substrates having exceptional chemical resistance, stability at elevated temperatures and high transmittance in the UV, visible, and infrared regions of the spectrum. Uniform and well-defined patterns of close-packed convex microlenses were formed in OrmoComp layers on H2 plasma treated FEP and ETFE substrates by UV-NIL replication of the metalized and liquid paraffin antiadhesive coated negative OrmoComp replicas of the master mold. UV-NIL replication was successfully performed at 7.1 kPa imprint pressure and 1100 mJ/cm2 exposure dose. Optical testing confirmed good uniformity and strong focusing ability of the replicated microlenses across the entire surface of replicas. Fluoropolymer substrates are especially promising for the use in harsh environments as a cheaper and lightweight substitute for quartz and glass. Moreover, flexible substrates enable further development of the proposed technique for especially efficient roll-to-roll replication.