Tunable Plasmonic Color Printing by Focused Ion Beam Nanofabrication

Abstract

Plasmonic color, which is a kind of structural colors, can be generated through the resonant interactions between light and metallic nanostructures. The manufacturing process of plasmonic color nanostructures is also addressed as plasmonic color printing. This thesis presents analysis over the color printing process on metallic thin film and metal nanocomposite material. The former structure is a kind of all-mental metamaterial manufactured by putting periodic nanocavities on silver thin film, during which the focused ion beam (FIB) milling process is involved. The desired colors can be printed on single silver film by tuning the nanocavity distance based on the principle of surface plasmon resonance. The later structure is manufactured by duplicating the nano-patterns from silicon mold fabricated by FIB to the surface of a kind of stretchable optical material, which is manufactured by mixing silver nanoparticles and polydimethylsiloxane (PDMS) in the weight ratio of 1:100. Due to the possession of the properties of both substrate material PDMS and filling material Ag nanoparticles, this nanocomposite material presents both high elasticity and good plasmonic color effect based on the principle of localized surface plasmon resonance. The color of material surface will change with the geometry deformation of nanostructures due to the stretching of the patterned nanocomposite material. A shape memory composite (SMC) actuator with nanopatterns on the surface was manufactured to illustrate how this printing technology is going to be applied in color based strain sensors. With the strengths of easy fabrication and large color tuning range, this design can be used in sensor applications and the future plasmonic color display technology.