Tuning near-field thermal radiative properties by quantifying sensitivity of Mie resonance-based metamaterial design parameters

The possibility of engineering near-field thermal radiative properties is investigated by adjusting design parameters of Mie resonance-based metamaterials. The sensitivities of surface polariton resonance frequencies, in both transverse magnetic and transverse electric polarizations, to parameters such as host medium relative permittivity and particle size and spacing (volume filling fraction) is determined. The sensitivity analysis is performed using a design of experiments method in combination with Mie resonance calculations and Clausius–Mossotti mixing relations. Particle size has the greatest effect on the resonance frequencies, while the volume filling fraction has the least. Based on the results from the sensitivity analysis, three metamaterials are selected for further analysis. The physics of these metamaterials is explored by calculating local density of electromagnetic states and surface polariton dispersion relation. As predicted by the sensitivity analysis, the local density of electromagnetic states and dispersion relation calculations show that Mie resonance-based metamaterials can be tuned to exhibit surface polariton resonance in the near-infrared spectrum. Energy density calculations show that surface polariton resonance in the near-infrared can be activated at temperatures as low as 800 K. Finally, a pathway to implementation of these metamaterials into macroscale engineering applications is proposed. Such metamaterials, with near-infrared surface polariton resonance, will significantly impact the development of nanoscale-gap thermophotovoltaic power generators for recycling waste heat into electricity. & 2013 Elsevier Ltd. All rights reserved.