Liquid metal-based tunable plasmon-hybridized nanostructures

Liquid metals form non-coalescent nanodroplets, with relative spatial positions static to each other and with sub-10nm inter-droplet gaps in the elastomeric substrate Polydimethylsiloxane (PDMS), owing to the presence of oligomers in PDMS. The plasmonic modes in these droplets interact with each other and lead to a hybridized mode, allowing the lowering of a single Ga nanodroplet mode from UV to the visible region of the electromagnetic spectrum. This further explains the blue shift of the optical spectra observed experimentally as the Ga-deposited PDMS is strained uniaxially. Herein, the individual modes have been obtained for the case of Gallium, a low-melting-point metal with a melting point at 29°C, and the hybridized mode energies have been determined. Plasmon hybridization not only explains the optical blue shift but also the spectral features of the experimentally observed optical spectra. These results indicate that our approach allows the application of UV-plasmonic materials in the visible region.