Materials for the preparation of polymer pen lithography tip arrays and a comparison of their printing properties

Polymer Pen Lithography (PPL) uses an array of polymeric tips, typically composed of poly(dimethyl siloxane), to transfer ink onto a surface and create patterns of soft molecules with micrometer to nanometer feature dimensions. In this study, tip arrays were fabricated from poly(methyl methacrylate), poly([methyl methacrylate]-co-[butyl methacrylate]), and poly(3- mercaptopropylmethylsiloxane), and used to pattern 1-mercaptohexadecanoic acid onto Au surfaces to determine the fidelity of pattern transfer by PPL as a function of the mechanical properties of the materials. It was found that the dependence between the applied force and feature edge length correlates directly to the mechanical properties of each of the polymers used to fabricate the tip arrays, where stiffer polymers have a reduced dependence between the applied force and feature size. This study demonstrates that PPL tip arrays can be composed of a wide variety of materials whose choice is determined by the desired printing application.