Optics and Nonlinear Buckling Mechanics in Large-Area, Highly Stretchable Arrays of Plasmonic Nanostructures

Abstract

Large-scale, dense arrays of plasmonic nanodisks on low-modulus, high-elongation elastomeric substrates represent a class of tunable optical systems, with reversible ability to shift key optical resonances over a range of nearly 600 nm at near-infrared wavelengths. At the most extreme levels of mechanical deformation (strains >100%), nonlinear buckling processes transform initially planar arrays into three-dimensional configurations, in which the nanodisks rotate out of the plane to form linear arrays with "wavy" geometries. Analytical, finite-element, and finite-difference time-domain models capture not only the physics of these buckling processes, including all of the observed modes, but also the quantitative effects of these deformations on the plasmonic responses. The results have relevance to mechanically tunable optical systems, particularly to soft optical sensors that integrate on or in the human body.

Decoupling optical function and geometrical form using conformal flexible dielectric metasurfaces

“…In these metasurfaces, each meta-atom is a high index nanopost acting as a short waveguide, which locally imposes a certain phase shift and polarization rotation. Several efforts have been made to transfer metasurfaces (mostly plasmonic ones) to flexible substrates with the aim of tuning their frequency response using substrate deformation [19][20][21][22][23][24][25]. Plasmonic metasurfaces, however, have low efficiencies especially in transmission mode, which in many situations make them impractical.Here, we introduce flexible metasurfaces based on a dielectric high contrast transmitarray platform that can be conformed to a non-planar arbitrarily shaped object to modify its optical properties at will.…”

Programmable and reversible plasmon mode engineering

“…The integration of plasmonic nanoparticles on top of elastomeric substrates has enabled tuning of the plasmon modes (5)(6)(7)(8)(9)(10), but the resonances remain broad because of radiative damping. Although long-range coupling in periodic arrays can result in extremely narrow resonances (full width at half maximum (FWHM) linewidths <5 nm) (11)(12)(13), the design criteria for these lattice plasmon modes are stringent, and the quality of the arrays is fixed at the time of fabrication.…”

A Mie resonant antenna with high sensitivity for force and strain measurement

“…EM metamaterials have potential for application in a wide variety of areas, in particular for sensing 10–15 . Inspired by the metamaterial approach, researchers have designed various sensors to diagnose strain or force telemetrically 2–4, 16–19 . Previously reported strain- or force-measurement devices typically comprise metallic resonators, such as split-ring resonators (SRRs) 2–4 , or complex metallic nanostructures 18–22 .…”

“…Furthermore, the sensors usually need to be adhered to the surface of the tested materials, which can cause measurement errors and lead to difficulties in measuring objects with complicated structures. Recent studies have shown that either linear or nonlinear performance can be achieved by introducing elastomer materials such as polydimethylsiloxane into metal nanoparticle structures 19, 23–26 , which has enabled the development of flexible EM devices that can be mechanically tuned with large strain deformation and have broad applications in biomedical engineering. These nanostructures usually require complex fabrication processes and operate in high-frequency ranges, such as near-infrared wavelengths 19 or in the visible region 21, 22 .…”