Multiresonant Selective Emitter with Enhanced Thermal Management for Infrared Camouflage

Area of Science:

• Metamaterials and Nanophotonics
• Infrared (IR) Technology
• Thermal Management

Background:

• Improving infrared (IR) applications requires tailored optical properties of metamaterials.
• Conventional IR camouflage materials with low emissivity in detected bands (3-5 and 8-12 μm) suffer from poor thermal dissipation and stability due to heat residue.
• Effective IR camouflage necessitates balancing low emission in detected bands with efficient thermal management.

Purpose of the Study:

• To introduce a multilayer metal-dielectric-metal (MDM) selective emitter for advanced IR camouflage.
• To achieve simultaneous low IR emission in detected bands and high IR emission in undetected bands for thermal management.
• To enhance the thermal dissipation capacity and thermal stability of IR camouflage materials.

Main Methods:

• Fabrication of a multilayer metal-dielectric-metal (MDM) selective emitter.
• Characterization of IR emission properties in detected (3-5 μm, 8-12 μm) and undetected bands.
• Comparative analysis of heat dissipation and thermal stability against conventional selective emitters and low-emission materials (e.g., Au film).
• IR camera measurements to demonstrate camouflage effectiveness at a surface temperature of 360 K.

Main Results:

• The multiresonance selective emitter demonstrated significant increases in heat dissipation (125% and 2910%) in the undetected band compared to controls.
• Substantial reductions in emissive energy were observed in the detected bands (72% for 3-5 μm, 83% for 8-12 μm) compared to a high-emission surface.
• Radiance temperatures were significantly lower than surface temperature in detected bands (314 K for 3-5 μm, 309 K for 8-12 μm at 360 K surface temp).
• Enhanced thermal stability was confirmed, particularly under low pressure and high heat flux conditions.

Conclusions:

• The developed MDM selective emitter effectively achieves dual functionality: IR camouflage and efficient thermal management.
• This approach overcomes the thermal stability limitations of traditional low-emissivity IR camouflage materials.
• The strategy offers a practical pathway for advancing selective emitters with applications beyond IR camouflage to diverse energy fields.