This project focuses on utilising block copolymers (BCPs) to fabricate silicon nanopillar arrays. The rationale for this was to use these silicon nanopillar substrates as a master to fabricate polymer nanopillars through replica molding techniques for applications in antibacterial surfaces. In the process, we aim to investigate reactive ion etch plasmas to modify polymer brush layers and to selectively remove polymer material from the surface. The development of a highly-controlled annealing process for polystyrene – block – poly4vinylpyridine (PS – b – P4VP) using a custom built solvothermal annealing chamber was undertaken. This work eradicated the disadvantages associated with static annealing methods and allowed the fabrication of BCP templates with hexagonal ordering. The removal of P4VP cores using plasma was investigated. In this work, oxygen, argon and nitrogen plasmas were investigated. A key finding was that nitrogen plasmas were successful in removing P4VP over PS, with further etch investigations into P2VP leading to the hypothesis that the nitrogen in the aromatic ring of P4VP plays a vital role in the etch rate. Preliminary results for the modification of a preferential PS brush layer to a neutral brush layer to control BCP orientation have been presented. This work showed that the wettability and surface energy of the brush layer was modified when exposed to an oxygen plasma. BCP annealing on top of plasma modified brush layers provided and insight into how the addition of oxygen effects BCP orientation. Replica molding methods were optimised using nanostructured cicada wings. This enabled polymer nanopillars surfaces to be fabricated. The swelling properties of these materials were investigated with the results revealing that the polymer swelling caused the nanopillar structure to increase in size. The fabrication of silicon nanopillar arrays using BCP templates of been demonstrated. These templates were transferred into the silicon substrate by converting the BCP into a hard mask and performing a silicon etch. Using optimised molding methods, polymer nanopillar surfaces were fabricated. These polymer surfaces were tested for antibacterial activity. Results showed nanostructured surfaces with pillars greater than ~50nm in height exhibited a greater antibacterial effect when compared to unpatterned surfaces and nanostructured surfaces with pillars less than 50nm.