Metasurface-Based Perfect Absorbers for Robust and Adaptable Coatings
Abstract
The Goal of the proposed project is to understand, design, and dynamically control the spectral behavior of nanostructured materials"" over macroscopic scales while utilizing environmentally robust materials. In particular, ultrathin coatings (-150 nm) will be crea"ted that have the ability to alter the spectral characteristics of the underlying material. The key to achieving this-and what sets" this proposal apart from previous efforts in the field-is spatial control on the molecular scale, with single-nanometer accuracy of"" critical distances between nanoscale components within the coating itself, achievable using chemical self-assembly techniques that"" are readily scalable and suitable for mesoscale integration. In pursuit of this, the project objectives are to (1) fabricate and ch""aracterize plasmonic perfect absorber structures utilizing environmentally robust materials coated upon a variety of large-area, con""formal, flexible, and/or stretchable surfaces; (2) uncover the possibilities and limitations of perfect absorber coatings based on f""ilm-coupled nanoparticles with respect to properties such as extinction ratio, behavior at oblique incidence angles, spectral width"" of response, wavelength range, and tailored spectra consisting of multiple resonances; and (3) integrate active materials into the" nanostructures to enable nanoscale coatings with a tunable and adaptable spectral response created by the application of external s"timuli such as heat, light or electric field. The approach to achieve these objectives is to exploit a unique, colloidally synthes""ized metasurface structure which has shown nearly perfect absorption (99.7%) in preliminary experiments, utilizing a simple, scalabl"e and conformal solution-based fabrication technique. The metasurface elements are composed of colloidally synthesized silver nanocubes coupled to a metal film with a sub-10 nm dielectric spacer layer in between. The resonance wavelength is easily tunable from t"he visible to the near-infrared spectrum, and the absorbers show good performance at oblique angles. In this project, to replace th""e use of noble metals, new environmentally robust materials suitable for naval applications will be designed, synthesized and chara""cterized, and tunable materials will be integrated within the coatings to enable novel adaptable nanoparticle-based structures.The" project is expected not only to enable robust and dynamically tunable coatings for the Navy but also to move towards smart nanomate"rials that adapt their properties depending on the environment. Critical for rapid transition from discovery to delivery, an afford""able and conformal, solution-based deposition technique is leveraged throughout the project to bridge the molecular-to-nano-to-macro" scale. This enables advanced coatings with control of absorption and emissivity of surfaces of arbitrary geometry and size with co"re properties derived from sub 10-nm-scale constructions. Owing to the high performance and ease of fabrication, these metasurface"" absorbers may also be integrated with existing technologies-e.g., photodetection and hyperspectral imaging-providing vast performan""ce improvements with respect to size, weight and power consumption.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2017
- Source ID
- N000141712589
Entities
People
- Maiken H Mikkelsen
Organizations
- Duke University
- Office of Naval Research
- United States Navy