Materials and applications of flexible metamaterials and plasmonics

Abstract

Given the ability to bend, stretch and roll like stretchable electronics, the newly developed metamaterial and plasmonic devices would open new chapters in functional optics. They can manipulate the electromagnetic waves in unprecedented forms and realize powerful applications like invisibility cloaking, sub-wavelength imaging, transformation optics and functional sensors etc. This review focused on the recent development in soft, flexible metamaterials and plasmonics that resonate from microwave to visible frequencies, various applications have been realized in filters, sensors and surface enhanced Raman spectroscopy etc. Optical structure designs are ranged from split ring resonators, multilayer fishnet metamaterials and nanoparticle arrays. Common soft substrates include polyimide, polydimethysiloxane, polyethylene terephthalate and polyethylene naphthalene. Their mechanical and optical properties were discussed. Compatible fabrication techniques such as conventional photolithography, electron beam lithography and a few newly developed nanofabrication techniques were introduced. Among which, nanoimprint and nanotransfer techniques that result in large area, low cost, high quality soft metamaterials and plasmonics are promising in wearable and tunable applications.