Nanoporous block copolymer stamps: design and applications

This thesis focuses on the surface patterning by using nanoporous block copolymer (BCP) stamps. Polystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) was used as model BCP. Nanoporous BCP stamps were fabricated by replication of lithographically patterned silicon molds. Nanopores inside of BCP stamps were generated by swelling‐induced pore formation. A method for scanner-based capillary stamping (SCS) with spongy nanoporous BCP stamps was developed. First, in the course of stamps design using replication molding of PS-b-P2VP against surface-modified macroporous silicon molds, PS-b-P2VP fiber rings remaining on the macroporous silicon molds were obtained that allow immobilization of water drops on the hydrophobically modified surfaces of the macroporous silicon molds. Water drops immobilized by these rings can be prevented from dewetting within the PS‐b‐P2VP fiber rings. Second, after spongy nanoporous PS-b-P2VP stamps had been obtained, preliminary experiments with non-inked PS-b-P2VP stamps revealed that parts of the stamps’ contact elements can be lithographically transferred onto counterpart surfaces. As a result, arrays of nanostructured submicron PS‐b‐P2VP dots with heights of ∼100 nm onto silicon wafers and glass slides were produced. Lastly, the SCS technique was developed, which overcomes the limitation of time-consuming re-inking procedures associated with classical soft lithography including microcontact printing (µCP) and polymer pen lithography (PPL) with solid stamps, as well as the limitations regarding throughput of scanning probe‐based serial writing approaches such as nanoscale dispensing (NADIS) and other micropipetting techniques. In addition, sizes of stamped droplets can be controlled by adjusting surface wettability and dwell time