【研究成果】2011

研究成果26

SEM images of Au nanorods/PMMA aggregated spots produced at a stationary focused spot of Ti:sapphire laser light. The laser intensity was 1.5 GW/cm2 and the exposure time was (a) 7.5 s and (b) 10 s, respectively. (c) High magnification image of (b). The spot consisted of Au nanorods individually wrapped by a PMMA layer. (d) Hypothetical mechanism of the formation of Au nanorods aggregation.

Fabrication of Au nanorod aggregates microstructures by means of a femtosecond near-infrared laser is demonstrated. The laser light was tightly focused into colloidal Au nanorods dispersed in photopolymerizable metyl-methacrylate (MMA) compound to induce two-photon polymerization (TPP). TPP of MMA glued the nanorods together to form solid microstrucures of aggregates. The laser light excited a local surface plasmon, resulting in confinement of TPP in the vicinity of nanorods. Concurrenly occurring optical accumulation of nanorods created a unique mechanism for the formation of nanorod aggregates into desired microstructures. This technique would be a clue for a novel micro/nanofabrication method for plasmonic materials and devices.