Self-Assembled Rippling Structure Based on Metal-Elastomer Composite for Tunable Plasmonics

We demonstrate that a periodic metallic wavy-structure can be easily fabricated on elastomeric polydymethylsiloxane (PDMS) substrates. The metallic wavy-structures are self-assembly formed by thermal evaporation of Ag on PDMS without any lithography processes. The size of the PDMS substrate with an aspect ratio (the ratio of length to width) higher than 2 are found to be necessary to self-assemble the one-dimensional metallic wavy-structure. The period of the wavy-structure is controllable by varing the thickness of the deposited silver film. The elastomeric-gratings can excite surface plasmon on Ag/air interfaces; the resonant wavelength can be tuned to a range of 3.5% by applying an external mechanical strain.