Fabrication of polymeric nanorods using bilayer nanoimprint lithography

A study was conducted to demonstrate a bilayer nanoimprint lithography (B-NIL) method with large-scale low-cost silicon (Si) molds of high-density nanopores. The nanopores were transferred from anodic alumina for fabricating free-standing polymeric nanorods with tunable lengths of 100 to 1 μm. A sacrificial polymer layer was introduced to the imprinting procedure to form free-standing nanoparticles with the functional polymer. Large-scale Si molds of high densities and ordered arrays of nanopores were fabricated by plasma etching using anodic alumina membranes as a mask, which enabled the fabrication of large quantities of nanorods. It was demonstrated that the same mold was to be used to prepare particles with different lengths by controlling the initial polymer thickness. Fluorescent nanoparticles were also fabricated by incorporating a dye molecule into the polymer matrix.