Towards nanoscale three-dimensional fabrication using two-photon initiated polymerization and near-field excitation
In this paper, we examine the feasibility of two-photon initiated polymerization (TPIP) using the enhanced field generated at the apex of a gold tip as the excitation source. We constructed three-dimensional polymeric objects to demonstrate TPIP using a previously described two-photon absorbing chromophore with a large two-photon absorption cross-section, ?, and an acrylate resin with our fabrication instrument. The minimum power capable of TPIP writing was determined with our instrumentation. As a model system for near-field excitation, NFE, we fabricated an array of gold tips on a glass substrate using nanosphere lithography. Using our minimum writing power as a guide, we exposed the two-photon excitable resin spun onto an array of gold tips. Polymeric structures were fabricated on the array of gold tips and the AFM images of the resulting structures suggest increased polymerization in the vicinity of the gold tips.
near-field excitation two-photon absorption microfabrication photo-polymerization