Radiative Thermal Transport with Nanowire-Based Uniaxial Electromagnetic Metamaterials
Abstract
Recent research progress has theoretically and experimentally demonstrated enhanced radiative heat transfer that exceeds far-field blackbody limit when two flat surfaces are separated by a vacuum gap less than the dominant wavelength of thermal emission. However, near-field radiative thermal transport between nanostructured surfaces is little understood. Most theoretical studies used effective medium approximation, whose validity in the near-field radiative transfer is highly questionable, while no experiment is reported to verify the enhanced radiative heat flux between two nanostructured surfaces with nanometer vacuum gaps.In the present project, we propose to theoretically and experimentally investigate the nearfield radiative transport between nanowire-based metamaterials. The nanowire array will be treated as a homogeneous but uniaxial medium, and accurate effective dielectric functions will be obtained from full-wave simulation rather than effective medium theories. Anisotropic wave optics will be incorporated into the fluctuational electrodynamics to calculate the near-field heat transfer. The near-field radiative transfer between nanowire arrays will be measured with vacuum gaps down to 100 nm, realized by fabricated dielectric nanospacers on the sample surfaces. The proposed experimental work will demonstrate the very first measurement of nearfield radiation transfer between nanowire arrays. The method will be further developed to study the effects of nanowire thickness and substrate materials in layered nanowire arrays on near-field radiative transfer.The proposed theoretical method will have a wide applicability to nanowire arrays made of arbitrary materials, geometry and shape, and provides a way to study these effects on the nearfield radiative transfer. The success of this project would facilitate the design and applications of nanowire arrays in near-field thermal radiation for energy harvesting, thermal management, thermal imaging and sensing.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2017
- Source ID
- FA95501710080
Entities
People
- Liping Wang
Organizations
- Air Force Office of Scientific Research
- Arizona State University
- United States Air Force