Octopus-Inspired, Flexible Plasmonic Arrays for Multi-Modal Laser Sensing

This work introduces a flexible, octopus-inspired hydrogel substrate engineered with plasmonic suction-cup microcavities for high-sensitivity laser-based chemical sensing. The hydrogel arrays mimic the negative-pressure adhesion mechanism of octopus suckers, enabling conformal attachment to rough, irregular, or inaccessible surfaces with feature depths up to ~300 µm. Plasmonic nanomaterials, including MXene sheets and silver nanowires, were incorporated into polyvinyl alcohol to form a multifunctional sensing membrane capable of multimodal laser detection. The platform simultaneously supports surface-enhanced Raman scattering (SERS) and laser-induced breakdown spectroscopy (LIBS), enabling molecular-level and atomic-level pollutant identification. The suction-cup design promotes efficient analyte capture by maximizing surface contact area, while the plasmonic enhancement architecture improves detection limits for a wide range of chemical species. This octopus-inspired design offers a versatile and high-performance sensing platform for environmental monitoring, biomedical diagnostics, and cultural heritage analysis.