Proton-fountain Electric-field-assisted Nanolithography (PEN)

Abstract

This chapter describes the implementation of Proton-Fountain Electric-fieldassisted Nanolithography (PEN) as a potential tool for fabricating nanostructures by exploiting the properties of stimuli-responsive materials. The merits of PEN are demonstrated using poly(4-vinylpyridine) (P4VP) films, whose structural (swelling) response is triggered by the delivery of protons from an acidic fountain tip into the polymer substrate. Despite the probably many intervening factors affecting the fabrication process, PEN underscores the improved reliability in the pattern formation when using an external electric field (with voltage values of up to 5V applied between the probe and the sample) as well as when controlling the environmental humidity conditions. PEN thus expands the applications of P4VP as a stimuli-responsive material into the nanoscale domain, which could have . technological impact on the fabrication of memory and sensing devices as well as in the fabrication of nanostructures that closely mimic natural bioenvironments.The reproducibility and reversible character of the PEN fabrication process offers opportunities to also use these films as test bed for studying fundamental (thermodynamic and kinetic) physical properties of responsive materials at the nanoscale level.