Feizpour Mehdi, Abbasi Sara, Thienpont Hugo, Ottevaere Heidi
Vrije Universiteit Brussel, Department of Applied Physics and Photonics, Brussels Photonics, Pleinlaan 2, 1050, Brussel, Belgium.
Vrije Universiteit Brussel and Flanders Make, Department of Applied Physics and Photonics, Brussels Photonics, Pleinlaan 2, 1050, Brussel, Belgium.
Talanta. 2025 Feb 1;283:127130. doi: 10.1016/j.talanta.2024.127130. Epub 2024 Oct 30.
Flexible SERS substrates, typically used on irregular surfaces, have unexplored optomechanical effects that could enhance performance. We developed a micromechanically bending structure, i.e. microbender, to study how bending affects SERS substrates' performance. Optical simulations of nanopillar arrays on micro-curved surfaces showed a 25-134 % improvement in mean-field localization at the pillar tips for arrays with pillar diameters of 0.4-1 μm, pitches of 0.5-0.8 μm, and heights of 0.5-4.5 μm. Raman measurements showed that SERS intensity increases when in a curved state due to enhanced light scattering, guiding, and field localization. A curved array of 6 μm tall pillars (0.5 μm diameter, 1 μm spacing) produced Raman intensities similar to dense single-voxel arrays with shorter 0.8 μm pillars (0.2 μm diameter, 0.2 μm gaps) in the planar state. This finding suggests that low resolution fabrication technologies can produce curved SERS substrates with similar performance to high resolution planar SERS, offering an alternative to the current "smaller is better" trend through post-fabrication manipulation.
