Cost-effective, large-area, reusable nanoimprint molds for polymer nanostructures

Abstract

In this paper, we report the use of a heptadeca-fluoro-1,1,2,2 tetrahydrodecyl trichlorosilane (HDFS)-coated anodic aluminum oxide (AAO) template as a low-cost, large-area, reusable nanoimprint mold. Coating AAO with HDFS increases the water contact angle (CA) from 20A degrees on a pristine AAO to 120A degrees on an HDFS-coated AAO, thus lowering adhesion of the AAO mold. Nanostructured polydimethylsiloxane (PDMS) could then be easily obtained by using the direct imprinting method on HDFS-coated AAO without any external loads. After nanoimprinting with an HDFS-coated AAO mold, the CA of the mold rarely changes (120A degrees to 115A degrees), thus demonstrating the possibility of a reusable AAO mold. The CA of PDMS increases up to similar to 15A degrees after nanoimprinting, and its transmittance decreases by 5 similar to 30%, compared with that of a flat PDMS film, in the full visible range due to the scattering effect, which implies that the optical pathway of incident light could be extended in the nanostructured polymer. Therefore, our nanoimprinting method is expected to enable a variety of applications in next-generation soft optoelectronics.