NIR-Reflective Black Photonic Films Designed for Effective LiDAR Recognition

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Conventional dark paints absorb visible and near-infrared (NIR) light, hindering LiDAR recognition in autonomous vehicles.
• Developing materials that selectively reflect NIR while appearing dark is crucial for advanced driver-assistance systems.

Purpose of the Study:

• To propose and evaluate colloidal photonic crystals as a novel solution for LiDAR-assistive coatings.
• To achieve a balance between low visible light absorption and high NIR reflectivity for autonomous driving applications.

Main Methods:

• Fabrication of colloidal photonic crystals via spontaneous self-assembly of silica particles in photocurable resin.
• Tuning the NIR stopband by controlling particle volume fraction.
• Incorporation of carbon black nanoparticles into interstitial regions to render films black and optimize optical properties.

Main Results:

• The developed black photonic films exhibit a tunable NIR stopband.
• Optimized carbon black concentration achieved low visible light transmission and high LiDAR intensity.
• Photonic films demonstrated superior LiDAR intensity compared to commercial dark paints and matched perylene black coatings.

Conclusions:

• Colloidal photonic crystals offer a promising, environmentally friendly alternative for LiDAR-assistive coatings.
• These films provide excellent durability, thermal stability, and non-toxicity.
• The developed materials significantly enhance LiDAR recognition capabilities for autonomous driving.