Curved Plasmonic Devices for Flexibility: Modeling, Fabrication, and Characterization

Surface plasmon resonance (SPR) used to implement highly sensitive sensors has widened its potential as a platform for flexible applications. Investigation of curvature effects on SPR is therefore crucial. In this work, we demonstrate SPR characteristics on micron-scale curved devices that may prove useful for flexible applications. Curvature effects were measured in curved plasmonic devices in the two orthogonal light configurations. The devices were fabricated experimentally using electron beam lithography and thermal reflow process in a range of curvature radius (
r
) for
r
= 0.288 ∼ 1.1 mm. Experimental results indicate that resonance characteristics are maintained largely as a constant for the perpendicular incidence regardless of the surface curvature. For the parallel incidence, a larger resonance angle was observed by 1 degree at
r
= 0.331 mm compared to the planar surface, which is accompanied by broadener resonance at a smaller curvature radius. Overall, the trends suggested by the experimental data were in good agreement with theoretical calculation. Our study provides valuable insights into the potential applications of conventional SPR devices on flexible platforms.