Novel dip-pen nanolithography strategies for nanopatterning

Dip-pen nanolithography (DPN) is an atomic force microscopy (AFM)-based lithography technique offering the possibility of fabricating patterns with feature sizes ranging from micrometers to tens of nanometers, utilizing either top-down or bottom-up strategies. Although during its early development stages the serial nature of operation of DPN restricted the patterning efficiency, the successful design and fabrication of AFM probe arrays have increased the throughput of DPN dramatically by enabling generation of patterns in parallel. Several advantages of DPN including (1) ease of generation of arbitrary patterns, (2) application to a variety of ink-substrate combinations, and (3) lower cost relative to other lithographic techniques, have led to many applications in different fields and the establishment of DPN as a popular tool for nanofabrication. This thesis contributes to the continuing development of the DPN technique, mainly focusing on two aspects. The first aspect, presented in Chapters 3-5, is to use DPN to fabricate metal-ion and (bio)-molecular patterns at micrometer or sub-micrometer scale onto monolayer-functionalized solid surfaces with different chemical immobilization strategies. Before performing all DPN experiments, microcontact printing (μCP), a well-known and understood simple and rapid soft lithography technique, was used first to confirm the usefulness of the ink-substrate interactions. The second aspect of interest is to develop an AFM tip surface-modification method for long-term DPN writing, as described in Chapters 6 and 7.